Interesting concept, and a really fun interface. The main issue I'm seeing is that the suggestions being surfaced are too close to what I've already selected - i.e., once I've indicated that I've read one or two of the books in the Hitchhiker's Guide to the Galaxy series, it should probably downrank the others, because while they are similar, it is likely that someone who's indicated they liked two of them has already read the others. There also seems to be an issue where the list of recommendations on the right still contains some of the books I've already liked.