> It would be nice to see all listeners to a particular artist or genre/tag. That would make it easier to befriend like-minded listeners. I imagine the success of this website will partly hinge on the edge density of the social network, so the more avenues you provide users to find friends, the better.

Great suggestion. Truth is, I was focused so much on the core stuff (indexing releases, implementing the bookmarking system, user profiles etc.) that the friend discovery aspect is almost non-existent. What you suggested seems like a great start though.