I was just poking around on Google books and noticed they've introduced a new feature, stolen straight from Amazon. When you pick out a title and click on About This Book, you're presented with a strip of related books in a manner that bears a lot of resemblance to Amazon's Also Boughts or Also Viewed. It appears Google is slowly upping its game. I was exploring a section on the Victorian era and Google seems to be doing a pretty good job of recommending titles that actually look interesting to read. The only flaw I can find is that it's somewhat hard to find the related books strip unless you already know where it's located.