Or more to the point, where do you find/choose books to buy, and why?
I think this is a great question. Kalayna Price raises it over at Magic District, commenting that an author's work doesn't finish with the printing of the book. There is publicity. There must be, fingers crossed, sales. Comments suggest recommendations from other readers (strangers!) at book review sites is a big influence. So too are covers. For all that a book is the purchase of words, it seems the visual image turns us on, or tunes us in.