Fat vs. skinny

So you're at the bookstore looking for something to read.  You're planning to actually buy something (you're not just browsing).  You spot two books that look interesting on the What's Hot In Fiction shelf.  You pick them up.  You scan the back cover blurbs and the first pages of both books, and they seem equally compelling.  The books are the same genre, written by authors you admire.


But one book is skinny (say, 275 pages).  The other book is fat (say, 550 pages).  You only have enough money for one book, and they're the same price.

Which one would you buy?