Just stumbled across an article (Deep Thinking about Weblogs) that mentions Weblog Bookwatch in its Weblogs and commerce section:
Their book list is compiled by a computer program that sifts the titles out of weblog posts across the Internet and ranks them by popularity. Once the final line of code for this program was written, the marginal cost for linking to fresh, kickback-generating sales became zero.What the author doesn't know is that the kickback (Amazon affiliate fees) from Weblog Bookwatch is roughly $10-$20 per quarter. That's not exactly covering the costs of maintaining it. But he is right, it's a way to aggregate information fairly effortlessly (once the code is stable) that could theoretically lead to paying for its own bandwidth with enough visitors. Right now, more bandwidth is spent searching weblogs than serving up links of books with affiliate tags. If that ratio was reversed the commerce angle might be there.