Why is amazon's book recommendation feature so bad?

Think about it: the data that amazon has collected - which books people buy, look at, browse, post reviews at, read customer reviews, etc - is a social scientist's wet dream. Amazon is uniquely suited to suggest books to you that you may not even know exist. Instead, my recommendations are almost entirely composed of books by authors that I've bought/put on my wish list.

Another frustrating feature is that its very difficult to search the lists amazon customers make. I was trying to list three or four of my favorite books so that I could see if someone had perhaps made a list with them included. Guess what - thats impossible to do this on the amazon site, as far as I can tell.

The sad thing, amazon could be so much better. If only their book recommendation and listsearch functions were better, I'd probably spend hours and hours on their website scouring for books. The only explanation I have is that bn.com is not giving them enough competition.