We've tested other models but collaborative filtering gave us the most "human"/natural results. Also, didn't Netflix toss the matrix factorization after the contest? IIRC they decided to keep their current algorithm.
So, like, instead of saying, "You liked Nosferatu? Well, other people who liked Nosferatu also liked Ran, so let's suggest that," it now goes, "Hey, that's a vampire movie! How about Blade?"