This tactic has been used in auto sales for years.
Selling customers at closing "undercoating, rustproofing and fabric protection" that are already part of the car, but get people to shell out extra coin for. Extended warranties fall into the same category. Just extra profit if nobody questions it.
I guess all those unemployed car sales-bodies have to take a job somewhere.
You can tune a piano, but you can't tuna fish. You can tune a filesystem, but you can't tuna fish. -- from the tunefs(8) man page