Bit of both. Amazon is easier when you're dealing with authors you know and categories you are comfortable with. Bookstore style incents me to explore outside my comfort zone. BUT .... bottom line: 1) I want an integrated, seamless transition. Not this amazingly complex jigsaw that Borders has now, and, 2) lower cost, which allows me to experiment. In fact, like music, I discovered several interesting authors and genres in the bargain basement!
Imperative that their website is designed by a librarian or a book enthusiast and not a tech wiz.