[alastairp]

In fact, ListenBrainz (partner project to MusicBrainz) is doing some stuff similar to what you mention about listening histories. We're using the data to generate similarity based on when songs are listened to each other in "listening sessions" along with other songs.

Follow the troi-bot user with a ListenBrainz account, and we'll generate you a daily playlist: https://listenbrainz.org/user/troi-bot

This is still very much work-in-progress, but we're doing as much as possible out in the open to solicit feedback from people.