I've noticed that there is a curious calculation going on in the minds of library patrons (my preferred term, although sometimes I will call them "users", but never, ever "customers". When I'm asking them if they'd like fries with their Nietzsche, then maybe I'll start calling them customers; until then I'll leave that loaded term to management and like-minded idiots) when they check out books at the Circulation Desk. There appears to be an inverse proportion between the size of a book and its net usefulness to the patron. Even if a book has a very high gross usefulness - say for instance a one-of-a-kind folio, an art book, or a definitive source for the patron's field of study or research- if it larger or thicker than the average book, the mental calculus begins. What would be cool would be to plot the curves of gross usefulness versus oversizedness and see exactly where that critical point was. Of course the personality of certain people would skew the data, but given a large enough sample I bet that would factor out.

This would make for a great article in the library science journals!