Man ... that's a hard one. Partly because Amazon sells so much more than books now. I've bought everything from tea kettles to power tools from them.
And, I have a feeling that there are a lot of people out there who have never so much as cracked a book that purchase goods from Amazon.
So, what sort of store would it be, versus what the consumer might expect? Would it be a bookstore where you could return a drill press you purchased online?
In the end, I think it would a complete and total mess.