Why streaming recommendations are different than DVD recommendations at Netflix
From Why Netflix Never Implemented The Algorithm That Won The Netflix $1 Million Challenge
An interesting insight:
when people rent a movie that won't arrive for a few days, they're making a bet on what they want at some future point. And, people tend to have a more... optimistic viewpoint of their future selves. That is, they may be willing to rent, say, an "artsy" movie that won't show up for a few days, feeling that they'll be in the mood to watch it a few days (weeks?) in the future, knowing they're not in the mood immediately. But when the choice is immediate, they deal with their present selves, and that choice can be quite different.
When I was a Netflix DVD subscriber the Seven Samurai sat on top of my TV for months. My present self never matched the optimistic view I had of my future self.
Xavier's blog post on Netfix recommendation is worth the read. Dealing with a household with widely different tastes, the importance of the order of presentation of recommendations