I second this. And if you decide you want to go really in-depth on recommender systems, I suggest taking a look at "Recommender Systems Handbook" (http://www.sp

I second this. And if you decide you want to go really in-depth on recommender systems, I suggest taking a look at "Recommender Systems Handbook" (http://www.springer.com/computer/ai/book/978-0-387-85819-7 http://www.springer.com/computer/ai/book/978-0-387-85819-7). It's basically a collection of scholarly articles on on the topic, so the approach is academic. But it's also the best resource I'm aware of for understanding what's state-of-the art across a range of aspects of recommender systems. (Also, although the price is a somewhat hair-raising $179, there are PDF copies of the whole thing floating around that are easy to find with a google search.)