What's up with music recommendations?

I just answered a Quora question about what, if any, are the differences in the algorithms that are behind recommendations for music and movies.

Of course, every media type is different. For instance, there's fundamental reasons why latent factor models works really well for music and movies, as opposed to location recommendations where I suspect graph based models are more powerful. People recommendations is another animal and I'm sure beer recommendations has its own domain-specific quirks.