SmartPlaylists lets you create and share iTunes playlists. The fact that iTunes doesn't let you do this clues us in to the fact that the guys running it don't really understand that direct network externalities are incredibly rare, extremely powerful, and a huge reason why people began using the net for music in the first place.

Services like this provide consumers massive gains, because they hugely reduce search costs, and offset the risk consumers face in buying experience goods from an industry they know is operating under extreme moral hazard. In fact, these kinds of search externalities are a huge reason file-sharing grew as fast as it did. Why is this difficult for the music industry to understand?

The article I just posted is about exactly this topic.