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Unique Visitors = 1/10th of Unique IPs?

CmdrTaco posted more than 8 years ago | from the that-might-be-pushing-it dept.


Max Fomitchev submitted a little blog entry where he proposes that the ratio of unique IPs to actual unique users is 10:1. This flies in the face of the numbers you usually see attached to these sorts of things. I'm not sure about the logic he uses to come up with these numbers either.

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Nuts. (-1, Offtopic)

Anonymous Coward | more than 8 years ago | (#15247363)

We should instead track based on credit card numbers. How many credit cards could a person have? Certainly not more than one.

10 was arbitrary (5, Insightful)

op12 (830015) | more than 8 years ago | (#15247364)

The 10 was a hypothetical...the only point was that you can't trust the number of recurring visitors that a site reports because they users come back with a different IP (obvious) and get counted twice. Couldn't one use cookies and IPs in combination to get a better gauge? The IP may change but the cookie would not. Sure some may delete it, but it'll still improve accuracy at least a little bit.

Re:10 was arbitrary (1)

Meagermanx (768421) | more than 8 years ago | (#15247430)

Exactly. How many people log into their webmail or their MySpace or whatever from their home computers, their laptops, their work computers, the library, their school's connection, etcetera? Almost everybody.

Re:10 was arbitrary (2, Insightful)

MikeFM (12491) | more than 8 years ago | (#15247438)

My experience is that a lot of users use cookie killing software that removes cookies every time the browser is closed or just reject cookies altogether. Also many users seem to use multiple browsers and computers even within small time periods. Counting unique visitors is really quite difficult. Still, if all site's play by the same rules on counting the number still has some meaning. Unique IP address within a given timeframe is probably a decent metric still.

Re:10 was arbitrary (2, Interesting)

op12 (830015) | more than 8 years ago | (#15247594)

My experience is that a lot of users use cookie killing software that removes cookies every time the browser is closed or just reject cookies altogether.

My bet would be in the grand internetscape, this number of users is actually quite small and that most do not reject or remove cookies (at least not often).

However, the point was a better gauge, not a perfect one. Requiring login would resolve most issues of users from different locations or even multiple users on the same computer, but few people are going to like a website they can't browse anonymously.

I think it's just interesting data for site owners and nothing more. I wouldn't overanalyze some site touting 3000 unique visitors a day or something.

Re:10 was arbitrary (1)

Penguin Programmer (241752) | more than 8 years ago | (#15247443)

I don't know about anyone else, but my IP address at any one location (home, for example) very rarely changes. Occaisionally, perhaps, if my internet goes out for a long period of time and DHCP gives me a new one, but not very often.

However, many of us visit the same site (/. for example) from many different places, even in one day. Today, I've already visited /. from two different machines with different IP's, and I'll visit it from one or two more by the end of the day.

So, I'm not sure which is the bigger cause of repeat visitors with different IPs each time: changing dynamic IP addresses or visits from different machines entirely.

Re:10 was arbitrary (0)

Anonymous Coward | more than 8 years ago | (#15247520)

And this doesn't factor in all the people connecting to the same website from behind a single IP (NAT). At my job for example, I know of at least 4 or 5 people who read slashdot from the same IP. So, in essence, what this guy just said is that unique IP's != unique visitors. Wow... brilliant. If anyone didn't come to the same conclusion after thinking for 5 seconds they're a moron.

I thought it was the opposite. (5, Insightful)

Black Perl (12686) | more than 8 years ago | (#15247488)

First of all, a DHCP server is typically going to give you the same IP address each time your computer requests it, unless there are more users than IP addresses, in which case there will be some shuffling. But that tends to be when there are more users than available IPs.

There are entire domains hidden behind a NAT device of some sort. This would be many users per IP address. TFA didn't mention this at all.

So I think TFA is indeed arbitrary, and also wrong.

Re:I thought it was the opposite. (1)

spyrochaete (707033) | more than 8 years ago | (#15247682)

Home internet users are usually grouped into big subnets of IPs that are constantly being shuffled around. IP addresses expire and reconnect on a schedule, houses have power failures, modems do something funny, or whatever. IPs in a huge pool are being retired and reassigned constantly. The bigger the pool, the lower the chance of obtaining the same one before someone else's modem nabs it.

If they offer it, ISPs charge extra for static IPs. Nobody would pay extra if it wasn't an issue.

Re:I thought it was the opposite. (5, Insightful)

the melon (89066) | more than 8 years ago | (#15247688)

Yeah, here at Sun there are nearly 40 thousand people that connect through 40-50 different proxy servers. That is a thousand to 1 in the opposite direction the article claims.

And yes, he seems to have no idea how DHCP really works. Even if your lease is expired you will get the same IP address unless the pool has been exausted and your address re-used. I see that as an extremly unlikely thing to happen because it would mean, as you say, that your pool is smaller than your installed base. If you pool is smaller then you will start having issues because x number of customers will always be without a connection because they can't get an address.

Had he mentioned Dialup users then I would be more inclined to agree because you are very likely to get a different address every time you connect.

Re:10 was arbitrary (1)

From A Far Away Land (930780) | more than 8 years ago | (#15247489) uses a cookie to determine if someone has visited before, and so people who don't retain cookies throws off my blog's stats. I see visiotrs counted as two, when clearly they must be the same person. Dialup with DHCP addresses also hampers accurate counts about who is returning, if they've deleted the cookie. And computer labs or vast networks like Community Net in SK use proxy servers, as does AOL I think.

Re:10 was arbitrary (1, Interesting)

Anonymous Coward | more than 8 years ago | (#15247513)

Couldn't one use cookies and IPs in combination to get a better gauge?

No. What happens when I visit the website from work, or from a library? What happens when I reinstall Windows? What happens if I disable cookies? What happens when my girlfriend uses my computer to visit your site?

Web statistics can only be trusted to measure server state. To measure things like number of visitors, browser marketshare, etc, you need to obtain your data by other means, e.g. surveys. If you try and use what your server sees to obtain this information, then not only will your statistics be wildly skewed, but they'll be skewed by an unknowable amount, making them absolutely useless.

People who proudly trumpet web statistics are ignorant. Some of them are wilfully ignorant - i.e. they'll try and say that if the numbers can be biased in both directions (i.e. you can undercount and overcount), then they cancel each other out. I refuse to believe anybody could actually be that stupid, so I tend to assume they are just sticking their heads in the sand because they like to believe the numbers, no matter how mistaken they are.

Every time I post this, I always get a bunch of people modding me down and complaining because I offended them by questioning their sacred web statistics. "How dare you say I didn't get three dozen visitors to my blog last week!" I really don't understand this unhealthy attachment to meaningless numbers.

Re:10 was arbitrary (1)

Anonymous Crowhead (577505) | more than 8 years ago | (#15247613)

Gah, no kidding. Everyone who has had to explain this to a PHB, please raise your hand. "But, they're the server logs! How can they be wrong? This PDF has been downloaded 1,000,000 times. Look - there are 1,000,000 lines in the log that have this pdf file in it. Broken up into chunks by the webserver? WTF does that mean? Nope, 1,000,000 downloads of this PDF. This is were we need to put the money. This is the most popular thing we have. People want this."


Re:10 was arbitrary (2, Insightful)

bbsguru (586178) | more than 8 years ago | (#15247561)

Oh Puh-lease! EVERYONE knows the REAL number is 11.32019 per IP address. This is just silliness! There is no magic number that works everywhere; fuggidaboudit. If it matters that much to KNOW the real number of unique visitors, ask each one for a scan of their right thumbprint, and then create a database. I thought so.

Crazy article (2, Informative)

TheLastUser (550621) | more than 8 years ago | (#15247595)

You can't trust web stats, that much I agree with. The rest is a bunch of hand waving.

DSL customers do not get a new IP every time they turn on their computer. Maybe some do, but my IP changes maybe once every few months, max.

He fails to mention the effect of NAT'ing and mega proxies, both of which are in heavy use and have the OPPOSITE effect. All of AOL emerges through a small number of IP addresses, clearly more eyeballs than IPs.

I agree that IP != eyeball, but that's it, there could be more eyeballs than ips or less, who knows, and it probably varies from site to site, based on demographic. There is no way to know for sure. Cookies will only tell you the number of computers.

nothing much here (0)

Anonymous Coward | more than 8 years ago | (#15247366)


If DSL_FRACTION = CABLE_FRACTION = 0.5 then we get

IPs = 5.5*Visitors or Visitors = IPs/5.5

thats the formula she uses to get the number of idea if the math is right,anyone who has an idea,please enlighten me

Re:nothing much here (2, Insightful)

GigsVT (208848) | more than 8 years ago | (#15247386)

I'm on DHCP on Cable. I don't think I'm the only one. I guess maybe the article wanted to show by demonstration how most statistics are made up on the spot.

Re:nothing much here (0)

Anonymous Coward | more than 8 years ago | (#15247415)

14% of all people know that

Re:nothing much here (3, Funny)

hotgigs (899872) | more than 8 years ago | (#15247480)

Last line of article: "So do not trust stats, they ARE inflated." Like I have always heard in regards to statistics: "Statistics are like loose women. You can do whatever you want with them" Although I don't suppose most of us on Slashdot would know much about women, let alone loose ones...

Re:nothing much here (2, Informative)

level_headed_midwest (888889) | more than 8 years ago | (#15247642)

From what I hear, most cable users are on DHCP. In fact, my cable provider doesn't even allow the option of a static IP whereas the DSL provider will (for an extra fee, of course.)

Re:nothing much here (2, Insightful)

zippthorne (748122) | more than 8 years ago | (#15247468)

Well it appears to make the assumption that the visits are sparse enough for the DSL Ips to change every time (and also that cable IPs are static. Mine is not, though it doesn't change for months at a time)

So, what IS the typical holding interval for a DSL ip?

as for properly estimating, If there are good enough statistics to have separate numbers for both {known, relatively static IPs over a month} and {known dynamic IPs} you could find the ratio of returning static IPs and normalize the dynamic ones to match that ratio.

In fact, I'd be surprised if this wasn't already being done for many sites.

On average.. (-1, Offtopic)

Anonymous Coward | more than 8 years ago | (#15247367)

how many refresh for an FP ?

so... (5, Funny)

gEvil (beta) (945888) | more than 8 years ago | (#15247377)

So, he's saying my website has 1/10th of a visitor?

Re:so... (1)

labalicious (844887) | more than 8 years ago | (#15247512)

Yes, in fact... Only my foot has visited your site and it was thoroughly bored with it.

Re:so... (1)

Ruvim (889012) | more than 8 years ago | (#15247659)

That's actually, ZERO Visitors, as you are not a visitor, but a host, so to say.

Re:so... (0)

Anonymous Coward | more than 8 years ago | (#15247672)

If I were even more exact, I would say that he has not more than -9/10 visitors. Gee, how I'm sorry...

Neighbor's Wireless (5, Funny)

Anonymous Coward | more than 8 years ago | (#15247382)

I help keep this in balance by using my neighbor's wireless, that IP has a load of unique users.

Cookies? (1, Insightful)

Anonymous Coward | more than 8 years ago | (#15247384)

Isn't this what cookies are for? Sure lots of people wash them. But I'm betting the majority of people do not.

cookies (-1, Redundant)

Anonymous Coward | more than 8 years ago | (#15247387)

Why not simply count your visitors with cookies?

Maybe not... (2, Insightful)

Anonymous Coward | more than 8 years ago | (#15247399)

I've hosted several servers from home for years at a time without my dynamic IP address ever changing, and I've known many others in the same situation. I think this 10x rule might be a bit extreme...

Re:Maybe not... (0)

Anonymous Coward | more than 8 years ago | (#15247523)

I've had a primary MX on a dynamic IP on a cablemodem. About the only time I had to change the DNS was when the ISP shuffles their network (about every 2 years).

Already considered. (0, Redundant)

locu (935130) | more than 8 years ago | (#15247402)

I think anyone in the tech sector knows this already. It's pretty common knowledge that people surf from multiple IP addresses. How about a solution instead? How about adding MAC addresses to stats, or modem_id's (whatever the equivilent to them is a to a MAC) and have webbrowsers send that data too then stats applications can have something more unique to identify a unique customer by than an IP address.

Re:Already considered. (2, Insightful)

Nos. (179609) | more than 8 years ago | (#15247437)

Because its none of your business (you being a web"master"). I understand that my Ip is broadcast, but I'm not going to use a web browser that sends personal information about me or my computer, every time I hit a site. I can use an anonymous proxy now, and refuse/delete cookies, and know that I am not being tracked. Besides, MAC addresses can be altered as well.

Re:Already considered. (1, Informative)

Homology (639438) | more than 8 years ago | (#15247446)

How about adding MAC addresses

Your MAC address survives at most until the next router.

Re:Already considered. (0)

Anonymous Coward | more than 8 years ago | (#15247454)

How about adding MAC addresses to stats, or modem_id's (whatever the equivilent to them is a to a MAC) and have webbrowsers send that data too then stats applications can have something more unique to identify a unique customer by than an IP address.

Why would I want my browser to send you identifying information? This makes no sense to me.

Re:Already considered. (1)

locu (935130) | more than 8 years ago | (#15247478)

The article is just stating the obvious. Just looking to present 1 of what will soon be many solutions to the problem probably. Nobody likes cookies, nobody likes sending personal data. There's always some critic to *everything* out there. And every advancement in technology always ticks somebody off.

Re:Already considered. (0)

Anonymous Coward | more than 8 years ago | (#15247600)

What about firewalls. I'm sure the 40 or people surfing at my workplace are all seemingly using the same IP to So perhaps it goes the other way - one IP equals 10 users.

Re:Already considered. (1)

ceoyoyo (59147) | more than 8 years ago | (#15247604)

Perhaps people should be a little less concerned with tracking other people? Why exactly should uber accurate unique visitor statistics matter to websites? How about a little less effort tracking your visitors and a little more generating something interesting for them to see when they do visit?

Re:Already considered. (1)

Adam Hazzlebank (970369) | more than 8 years ago | (#15247610)

Because a) It would be a gross invasion of privacy b) It doesn't solve the problem of a user surfing from multiple computers and c) It's technically infeasible.

Re:Already considered. (2, Funny)

dietrollemdefender (970664) | more than 8 years ago | (#15247614)

...can have something more unique to identify a unique customer by than an IP address

So says the AC.

Re:Already considered. (2, Informative)

level_headed_midwest (888889) | more than 8 years ago | (#15247669)

That's called Internet Protocol Version 6, where some of the address is your MAC address.

Logging in from home vs. work PC (1)

hotgigs (899872) | more than 8 years ago | (#15247403)

So if I access a site at work and then access it at home, that's two IP's (two different computers and two different ISPs) but one user. Seems a bit high to say 10 but I could see 2 - 3...

NAT? 10 is too high! (1)

Mr.Ziggy (536666) | more than 8 years ago | (#15247515)

There is no mention of NAT in his analysis. NAT is even included in some DSL modems these days from SBC. Lots of companies will have 100+ computers behind a single IP address.

Why is this guy's post news? Can I sit around and write bad formulas to get my blog linked by slashdot too?

Re:NAT? 10 is too high! (2, Interesting)

RingDev (879105) | more than 8 years ago | (#15247591)

No joke, we have 800 people going out over one IP from here. Kinda a pisser when I hit the 'slow down cowboy! you just posted' message. As much as the stats are inflated by dynamic IPs and multiple logon points, they are deflated by NAT and Proxies.


Assume = ASS + U + ME (1)

Orestesx (629343) | more than 8 years ago | (#15247407)

"Presuming that the latter have static IPs the former draw different IP from some pool each time they connect." I have dsl and according to, my dynamic IP host, my ip was last updated on April 13. Just because someone is using PPPoE doesn't mean that each time they visit your site they will have a new ip.

Am I my clothes or my reward card? (1)

spyrochaete (707033) | more than 8 years ago | (#15247410)

I guess it depends on the definition of "visitor". Maybe the site tracks unique IP addresses, or maybe it ignores them where the client has a permanent cookie installed.

However, I can attest that my ADSL connection is pretty DHCP heavy. Sometimes my IP won't change for weeks, but I've had 5 or 6 IPs in 24 hours on several occasions.

The post is a bit misleading (1)

mapkinase (958129) | more than 8 years ago | (#15247416)

Actually, the article is about exhaggeration of the number of visitors. Number 10 is just a vague unsubstantiated number given in the blog entry without supporting data to illustrate the magnitude of that exhaggeration.

Use cookies (1)

Bruce Perens (3872) | more than 8 years ago | (#15247419)

IP addresses do not correspond to users because of dynamic IP and proxies.

Cookies are a much better indicator of what browser you are communicating with.

Also, most spiders don't bother with cookies, so that's another way to tell something isn't a real user.

Unfortunately, some users disable cookies. And then all you can do is fall back on their IP address.

It would be nice to see cookie-tracking support in Open Source stats engines like awstats.


But... (5, Funny)

xpird (207937) | more than 8 years ago | (#15247422)

Can he find a formula for the number of /. articles posted vs. the actual unique articles?

Stopped reading after the first sentence. (1, Offtopic)

mightybaldking (907279) | more than 8 years ago | (#15247424)

Both a grammatical and a math/logic error in the first sentence!

Maybe (1)

Kethinov (636034) | more than 8 years ago | (#15247427)

I think the moral of the story here is that you can glean no true information as to how many visitors your site really has by unique IPs. This convenient unique visitors = 1/10th of unique IPs idea is no more accurate than simply assuming each new IP is a new visitor. There will be people who visit your site from 10 different locations and thus 10 different IPs, and there will be whole families on one IP visiting your site. Or perhaps one of those 10 different locations one person uses is used by others. Since we have no way of knowing these things, any sort of formula is as inaccurate as the next.

Nonsense (1)

MrNougat (927651) | more than 8 years ago | (#15247431)

I see what the guy is saying - dynamically assigned IPs at clients mean that one person can view a site from multiple source IPs over a period of time. Both DSL and cable use dynamic IPs - but they are not often disconnected/reconnected, and when they are, DHCP is likely to pull the same IP address back anyway.

Besides that, think of all the people at work on internal LANs, each presenting the same public IP source address to the same web server. This effect more than makes up for the dynamic IP nonsense the blogger spouted off.

Maybe he's just mad about the size of his epenis, and is trying to compensate with illogic.

WTF? (3, Insightful)

giorgiofr (887762) | more than 8 years ago | (#15247432)

This argument is flawed. Logging to Slashdot now from my house and two hours from now from my friend's house should count for two visits, and so it rightfully does. The article writer seemed to have a problem with this? ZOMG 2 different IPs...
And if my IP has changed but I'm still here... that's because I haven't surfed for many hours at least otherwise the lease will be renewed and the address will stay the same. So it should still count for two visits. Duh.

Re:WTF? (0)

Anonymous Coward | more than 8 years ago | (#15247466)

two visits yes but ONE PERSON you moron. thats what the writer is trying to say.
most site stats say unique visitors but in fact its unique ip addresses.

Re:WTF? (1)

gEvil (beta) (945888) | more than 8 years ago | (#15247473)

So you are saying that by going to your friend's house, you are now a different person (aka, a different unique visitor)? It may count as two separate visits (which is not what is being argued here), but you are still the same unique visitor. Counting IPs alone does not provide an accurate representation of how many unique visitors view a site. Your example only helps to demonstrate this.

Re:WTF? (1)

mightybaldking (907279) | more than 8 years ago | (#15247481)

It all depends on what we are counting. These numbers are primarily used for advertising. I can show your ad once to ten different people or 10 times to one person. Which do you prefer? Are we counting unique visits or unique visitors? You are correct if the former, but wrong if the latter.

Re:WTF? (1)

the phantom (107624) | more than 8 years ago | (#15247516)

Two things:

1) He is interested in counting the number of unique visitors to a site. Not unique computers. If you visit a site from a home computer, a work computer, and a computer at some internet cafe somewhere, it will show up as three different IPs, and be counted as three different unique visitors. However, you are only one person, so, if we are concerned with counting unique visitors, it has just overcounted you by 2.

2) Also, even if you are using just one computer, there is a high likelihood that your IP will change over the couse of a month (if not more often). Assuming you are on DSL (cable, as well, but he ignores this fact), you are probably getting an IP address via DHCP, which means that the server issueing that address could issue a new one every time you connect. Over the course of a month, you may get several addresses, each one counting as a unique visitor. Again, you are being overcounted.

Less (1)

teeseejay (967400) | more than 8 years ago | (#15247436)

For sites with recurring traffic there are at least 10 times less unique customers than there are unique IPs.
The word you're looking for is "fewer," buddy.

Re:Less (1)

mightybaldking (907279) | more than 8 years ago | (#15247505)

And what does 10 times less/fewer mean?

Re:Less (0)

Anonymous Coward | more than 8 years ago | (#15247656)

The same thing bugs me as well. There are just too many mathematical luddites out there who had a bad experience with fractions in the fifth grade and now can't wrap their brains around phrases like "one tenth as many as". So, instead, they say "ten times fewer than", or n = m - 10m = -9m.

It's like saying "ten times as many as" versus "ten times more than". The first case is as intended, n = 10m. But the second case (though it's usually not used this way) should be interpreted as n = 10m + m = 11m. (Of course, in this case, when the multiplier is large, the inaccuracy is small.)

The other one I hate is "a million and a half", especially as applied to people. Things must be pretty uncomfortable for that extra half a person, unless the speaker really meant "one and a half million".

Comcast doesn't change (1)

Solkre (787360) | more than 8 years ago | (#15247440)

I have Comcast Cable and to be honest, they never assign me a different IP address. I've had the same one for 6 months, the entire time in this new appartment. My old connection was the same, DHCP getting the same IP address over and over again. Does this guy account for my wife and I visiting the same website, being two different users, yet having a shared IP address?

fyi (1)

hurfy (735314) | more than 8 years ago | (#15247445)

Fixed 4:1 ratio here tho i can't speak for anyone else.
1 office and 3 home computers.

10 seems a little excessive, timeframe probably matters to actual ratio: unique per day? month? year?

The author left out surfing from work (2, Insightful)

Trails (629752) | more than 8 years ago | (#15247447)

I do most of my news browsing at work, where several hundred people show up as one IP (home computer is exclusively for WoW).

Besides, the assumption that stated unique visitors = actual unique ip's is innacurate. Lots of companies track users with some kind of UID cookie, for more accurate stats. True, this isn't perfect either, and will reset when users wipe their cookies or it expires, but is probably closer to the real number than ip's.

Okay... and? (1)

the_skywise (189793) | more than 8 years ago | (#15247449)

Ooh, wow... IP's aren't good indicators of uniqueness... I'm sure the Slashdot editors will tell you how valid that is when they're troll hunting.

But I don't think dynamic DSL IPs are that big of a problem. What about DSL users that are connected 24/7? My DSL provider rarely kicks me off and I can hold the same IP address for weeks.

What about laptop users at wireless cafes or users who post/read from work? Surely the same IP that reads a tiny website from home is likely also the "same IP" that reads it from a nearby workplace.

Plan 9 (0)

Anonymous Coward | more than 8 years ago | (#15247451)

If only the same was true with our little OS [] over here [] .

Erm. (1)

Rob T Firefly (844560) | more than 8 years ago | (#15247457)

A) He's talking about IPs reported in site visitation stats, not available IPs "out there."

2) He skips a few major technical details about the IP system itself.

d) He's mulling over a random loopy theory in a personal blog post, which isn't quite news. If it were, I'd be William Randolph Hearst by now.

More than IP (1)

Billosaur (927319) | more than 8 years ago | (#15247459)

If you are only using IP to generate your visitation metrics, then you're fooling yourself, for the reasons outlined in the blog. You can't guarantee an IP is unique to a user, any more than you can guarantee that a user is unique to an IP (think Internet cafe or library; different users, same machine with potentially the same IP)

You have to use a combination of log data to try and scope out exactly who's visiting: IP, browser type (can't count robots in your stats), membership id (if the site uses/requires it), and possibly cookie data (you assign a unique id when a user visits the site and they carry that data to every page). Here's a good breakdown of metrics processing [] and its pitfalls.

Max has just learned about DHCP (1)

upside (574799) | more than 8 years ago | (#15247462)

... but didn't read the detail. A DHCP client gets the same IP address it had previously, so unless the pool is in short supply of free addresses it will get the same address as before.

And why does he suggest that DSL clients have static addresses while cable users have dynamic ones?

Also, most home users (I'm allowed a presumption too) have routers instead of bridge/modems or PCI card modems, and they are kept on all the time. While the router is powered on it will keep renewing the existing IP address.

I have a dynamic IP address but it's stable enough to run servers on it.

What about proxies? (0)

Anonymous Coward | more than 8 years ago | (#15247464)

AOL represents a large chunk of traffic and all users appear to come from one of a dozen proxy servers. Did he factor this in?

No fucking duh (1)

SmallFurryCreature (593017) | more than 8 years ago | (#15247474)

IP says very little. Dial-in users (yes they still exist) get a new one every time they dial-in.

I am a little puzzled by his assumption that DSL users get a new ip while cable users have a static one. I had a DSL account with a static ip and a cable with a changable one.

Also if you got a good ISP that doesn't drop your always on connection you won't be changing your IP all that often. Hell even my crap cable provider rarely changed my ip.

So no, for a "large" site you can't really determine unique visitors by ip. That only works for really small sites wich maybe get one visitor per ISP worldwide.

Even if IP was unique that still doesn't account for proxies. I have personally had to explain a couple of times to customers that no user X wasn't reloading the site constantly, that is the proxy for a university.

So my conclusion? Wake up and smell the coffee. Everyone who knows anything about measuring site metrics know that you can't make any claims based on ip's.

His 10:1 claim is just random guessing.

If you absolutly must know then you need to do what newspapers do when they study how many people read their newspaper (and therefore see the ads) vs how many newspapers are sold. Take a wild stab at it and choose the figure you think your are going to get away with.

Re:No fucking duh (1)

drinkypoo (153816) | more than 8 years ago | (#15247637)

Also if you got a good ISP that doesn't drop your always on connection you won't be changing your IP all that often. Hell even my crap cable provider rarely changed my ip.

Even if it does drop connection, if you renew your lease within the TTL, you'll get the same IP anyway, unless the server is configured otherwise.

On Comcast, my IP only changed if I brought up machines out of order. So long as my server was the only thing hooked up to the cable modem (to do firewalling and NAT) then the IP never changed. If it went down or I was trying to do some troubleshooting and hooked up a different PC, then it got the firewall's IP, and the firewall got a new IP or something like that. Very strange.

wait a sec (4, Interesting)

hurfy (735314) | more than 8 years ago | (#15247479)

I forgot something.
What about the other way?

Do they see the 10 people on the office NAT as one IP ?!?

That would skew it in the other direction and average things out wouldn't it? Now 10 is definately excessive.

Don't NATs skew the results too (1)

joeflies (529536) | more than 8 years ago | (#15247496)

If you have a NAT and only one IP facing the net, but a bunch of machines using network address translation, can the web site determine how many unique users there are attached to that IP?

There's a kernel of an idea there... (0)

Anonymous Coward | more than 8 years ago | (#15247497)

...which is that most ISPs deliver dynamic IP addresses, so users very well may be drawing multiple IPs over the period of time that they visit a website. But instead of running with idea and doing something useful with it, like conduct even a limited study (corrolate IPs & cookies, etc), he simply pulls some numbers out of his ass.

It's not so hard to come up with ideas like this - the real work is in verifying the idea, or coming up with a helpful method for figuring how those who care about such numbers can figure out what the real numbers are like.

It's lazy journalism when (1) the guy with the idea doesn't do any kind of validation of his concept before publishing, and (2) a big news site like Slashdot simply picks it up and runs shoddy work like this, tossing out a very potentially inflated 10x number...

Who cares (1)

Jesus IS the Devil (317662) | more than 8 years ago | (#15247508)

Nobody knows exactly how many true unique visitors there are to a given website. And given the various ways to determine what is "unique", this muddles the pie further.

However, the important thing is, advertising rates aren't affected since they have been market-corrected for this. If an advertiser can make money, he will buy. If he can't, he won't. Whatever the true number is, it's already been factored in.

NAT (0)

Anonymous Coward | more than 8 years ago | (#15247509)

What about NAT and proxies?

AOL uses HTTP caching (2, Insightful)

QuietLagoon (813062) | more than 8 years ago | (#15247517)

All of the millions of AOL users visit websites via a couple of hundred cache servers. You won't see a lot of different IP addresses for the AOL visitors to your site.

I wonder if the other major ISPs do the same.

Re:AOL uses HTTP caching (3, Informative)

drinkypoo (153816) | more than 8 years ago | (#15247677)

I wonder if the other major ISPs do the same.

No, most of the major ISPs just have an agreement with someone like that handles dialin for them, and they only do caching for customers who pay for "high speed dialup" which is to say browsing through caching proxies that degrade image quality in order to reduce bandwidth consumption due to page loads.

Counter-example (1)

Bottlemaster (449635) | more than 8 years ago | (#15247532)

The building I work in houses about 3,000 employees. We all access the internet through a proxy and so appear as only a few unique IPs. Perhaps situations such as this could make up for the home users' DHCPing.

static/dynamic (0)

Anonymous Coward | more than 8 years ago | (#15247534)

yeah, i agree with the other commenter who mentioned comcast. as a cable customer, although i technically have a dynamic ip address, i don't really. it changes maybe twice a year. although i would say that perhaps 2 to 1 or 3 to 1 would be a decent guess, maybe.

and he is totally not considering situations where it works the other way around. that is to say, he is not considering situations where different visitors come from the SAME ip address (as opposed to the other way around). if a huge lan exists, such as a university, which is behind a router, and 100 people from that lan visit the site, they will all appear to have the same ip. i think, right? taking that into consideration may throw the numbers in the opposite direction.

Just count visits.. why count ip's? (1)

xiando (770382) | more than 8 years ago | (#15247537)

If you use [] then it counts number of visits, the same IP is still the same visit if the user of that IP (re)loads a page within 30 minutes. After that it's a new visit... And it should be safe to assume one visit is one user. Saying that 1:10 is the ratio for IP/users is simply saying that every user will visit the site ten times - which seems like a worthless number without limiting it to a time-period and also, the number seems to be taken out of no-where.

Re:Just count visits.. why count ip's? (1)

dgatwood (11270) | more than 8 years ago | (#15247607)

Except that with that scheme, AOL is about one user, more or less.

Re:Just count visits.. why count ip's? (2, Funny)

ceoyoyo (59147) | more than 8 years ago | (#15247633)

Sounds accurate to me. Many hands, one brain. Or near enough.

NAT / DHCP (1)

f(x) is x (948082) | more than 8 years ago | (#15247541)

Conversely, NAT, Proxy servers, CDNs (like Coral, CoDeeN), etc. decrease the number of IP addresses that access a page while having a large number of users see the content...

Stupid, stupid, stupid... (1)

C10H14N2 (640033) | more than 8 years ago | (#15247545)

Single IP addresses could be multiple people. Check.
Multiple IP addresses could be individual people. Check.
Cookies cannot be trusted to be persistant, since people routinely clear their caches. Check.


Not all DSL customers are on dynamic ip.
Not all cable customers are on static ip.
The reverse of the above is also not true, so why even get into that?

So, what can we learn about IP address->Unique visitors from the above collection of information? ABSOLUTELY NOTHING.

However, you could come up with a reasonable approximation if you went to the effort of constructing a sample of known individuals and recorded their behavior and against the selection of IP addresses they use throughout a day/week/month/year. Hell, take a site like /. and run the stats on registered users. THAT would be [vaguely] useful. This, on the other hand, was just pure, pull-it-out-of-your-butt speculation.

Um... duh? (1)

UP_Minstrel (70371) | more than 8 years ago | (#15247554)

Can we get a "From the 'Well, Duh' department" subheading for things like this?

Or, to completely skew his numbers... (2, Insightful)

Dynedain (141758) | more than 8 years ago | (#15247565)

We have 54 employees going through one firewall, and having one external IP address. On our company website, only that one IP address shows... So for that IP, it is not 1/10th of a unique visitor, it is 54 unique visitors. His numbers are baseless and skewed.

This is pointless (1)

Who235 (959706) | more than 8 years ago | (#15247573)

You can use statistics to prove anything.
40% of people know that. . .

Re:This is pointless (4, Funny)

Churla (936633) | more than 8 years ago | (#15247651)


But 37.5% of all stats presented by people are made up on the fly.

Only about 2.31% of people know that by adding numbers after the decimal point the average person considers the number "more credible".

how about the opposite problem? (1)

danpsmith (922127) | more than 8 years ago | (#15247574)

How about the people who connect from behind a router and have the same public IP, wouldn't that have the opposite effect. Sure these people _look_ like the same user, but could easily be a lot more than that.

If I send my sister a link on our home network, she could go to the site and it looks like the same visitor, etc. Everyone forgets about this too. Surely unique IPs != unique visitors, but it is somewhat close.

Caches, Proxies, NAT, etc. - weak article (1)

xmas2003 (739875) | more than 8 years ago | (#15247584)

While there's some validity behind what the article says (althought the 10x is ridiculously high IMHO), he fails to mention the other side of the equation which is multiple visitors from the same IP address. Your home network is almost certainly NAT'ed ... and Corporations are using proxies more and more for outbound connections. I.e. I know of one Fortune-50 company with a couple of hundred thousand employees that has a total of SIX (!) web proxies. You also see this with cache servers, especially stuff like AOL.

I agree you don't REALLY know for sure what the ratio of unique IP's to actual human visitors are (even assuming you filter out the BOTS) ... but my guess is that it is actually pretty close to 1:1 ... and in fact, unique IP's may actually undercount the number of unique visitors.

So let me get this straight (1)

GauteL (29207) | more than 8 years ago | (#15247586)

This random blogger (*) proposes something fairly wild without any proof whatsoever. Slashdot reports it simply because it is a wild guess.

Hmmm... I think I'll guess that there are only 10 unique internet users in the world excluding Comic Book Guy [tm], maybe that will get me reported on Slashdot giving me 10 hits of sweet, sweet advertisement money.

(*) Well, I've never heard of him.

Not true (1)

BadassJesus (939844) | more than 8 years ago | (#15247589)

There is about 500 people in my city routed throught one IP at our popular ISP in my city that makes 1 : 500 unique IP to unique user ratio, now consider many providers use this kind of routing.

At Wikipedia for example I saw my IP address under our local subject edits many times, never touched myself the article.

More datapoints needed (1)

satsuke (263225) | more than 8 years ago | (#15247596)

I'd say he'd have to look at a specific population.

Among college students and younger, it may very well be 10:1, or worse.

For those of us accessing from work and home. That will be 2:1 assuming the same site.

For those of us behind corporate firewalls or other traffic aggregate points. It could very well be 1:1000, or higher.

Without some other data point, unique IP address statistics are next to worthless, except in "We had xxx,xxx average daily last month and xxx,xxx + xx,xxx average daily this month.

unique IPs are so 1999 (1)

sednet (6179) | more than 8 years ago | (#15247612)

there are lots of challenges to accurately sizing an audience. i think that acceptance of audience size based solely upon unique IP addresses waned around 1999 when methods employing javascript and cookies came into vogue. there's always the option of counting registered users too.

all of these techniques help quantify unique users and monitor the trends in their online behavior. as far as noise in unique IP counting, i think that the biggest issue with relying soley upon unique IPs is that a simple count of unique IP addresses will include all robot noise. the major web searche engine spiders will not influence this count much, but the gratuitous IPs logged by script-kiddie bots can eclipse the human traffic on smaller sites.

Sounds familiar (1)

smooth wombat (796938) | more than 8 years ago | (#15247640)

This talk about tracking people and determining the amount of visitors to a site is somewhat dated. Here is an article from October of 2005 in which, astonishingly, it is revealed that people are deleting their browser cookies so when they go back to a site they are counted as a unique visitor even though they may have visited the site yesterday.

What the author is pointing out is merely the obvious: when a site says they have X visitors they're making a guess. In fact, this link [] from April 30th both explains and shows why web site statistics are not accurate.

This need to say how many visitors a site has is nothing more than marketers trying to justify their costs. The trend to shove commercials down our throats using every conceivable idea including the possibility of preventing you from switching channels when a commercial comes on [] serves only the marketers since they're the ones who are reaping the most from inflated statistics.

Two factual flaws (0)

Anonymous Coward | more than 8 years ago | (#15247652)

Firstly, cable users while on DHCP keep that address for weeks, thus one unique IP is one unique visitor. Secondly, I'd wager that a huge portion of internet surfing occurs at the workplace, which is masked behind a SINGLE IP: an enterprise of 5,000 or 10,000 employees is represented as 1 unique IP.

  Back in the day of modems and less inet prevailance, I generally thought the numbers balanced out. Today, I think there are many MORE visitors that unique IPs.

The Problem (1)

blueg3 (192743) | more than 8 years ago | (#15247665)

I almost knew not to read the article on the basis of the statement "the logic he used". The article did not disappoint. The logic he used is irrelevant. The whole argument is pointless because he tried to argue it logically. There are plenty of ways to inflate or deflate this number, however, as above comments have pointed out. One should not try to come at the answer with logic. Just measure it. (Yes, measuring it is not necessarily easy, but difficult-to-obtain right answer is always better than an easily-argued wrong one.)

NAT? (1)

NewmanBlur (923584) | more than 8 years ago | (#15247667)

I'm no expert, but I have about 20 people in my office, connecting through the net through a NAT'ed firewall. If we all looked at this guy's blog at work, he would technically have 20 unique visitors coming from a single IP address, so that would actually deflate his number of visitors based on IP address. It seems like Max's law is a little one-sided.

Well then why the fuck did you post it Taco? (0, Flamebait)

hellfire (86129) | more than 8 years ago | (#15247680)

I'm not sure about the logic he uses to come up with these numbers either.

News for Nerds! News! This isn't news. This is a random and arbitrary article that passes itself off as fact when it's just speculation. That's not news! Why the hell did you post it Taco if it isn't news???? Please.

Webmasters the world over know that the numbers we get aren't entirely accurate because of DHCP servers, NATs, and all the things we for IP addressing. That's not news and no webmaster really needs to be reminded of it!

What would be news is a statistical study that tries to provide facts to back up this 1/10 number, or a new, more accurate way to count people who visit your website.
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