Amazon now has a vast database of customers' preferences and buying patterns, tied to their e-mail and postal addresses. That relationship has traditionally been monopolised by the bookshops, and even they rarely keep track of what individual customers like. Amazon offers publishers a more immediate link. On the left side we have lots of products, on the right side we have lots of customers. We're in the middle making the connections.
Readers find books or books find readers.
As a former financial analyst, he picked books because existing margins and distribution patterns seemed most favourable to an online business. In future, Amazon may expand into music and videos. Once you understand the model, the applications seem almost limitless.