I've written between three and ten custom answers for each college to which I have applied. For the schools with more, there are usually three extra essays plus a bunch of short-answer questions. I've also applied to a good few honors programs, which have about three additional essays apiece.

The only thing the common app does is standardize the name/dob/address form that's two pages of paper anyway. The essays, which are by far most of the work, are mostly different. Oh, and the schools all still charge full application fees.