I can see that metadata about the movies becomes worthless, because there is already a wealth of data about each movie entity in the dataset. However, metadata

I can see that metadata about the movies becomes worthless, because there is already a wealth of data about each movie entity in the dataset. However, metadata about the users should be fruitful since each user has fairly few data points to use for prediction. Take for example two users who have each rated only Wall-E, and they both rated it a 5. Now, given Jet Li's "The One", what prediction do you give for each user? It is unlikely that two real people with this one data point on Wall-E would have the same outcome on "The One", so any additional data that can help to statistically separate the people can only help your case. For example, is the person male/female? What are the person's favorite genre's (something netflix collects), even things like did the person sign up for 6-at-a-time or 2-at-a-time might correlate slightly.