Populate a http://developer.echonest.com/docs/v4/tasteprofile.html with the listening history and you can use it for dynamic playlisting using the spotify catalog. That is as long as echonest matches the song metadata to an id.

http://static.echonest.com/enspex/web/ChillRadio/ linked from the demos shows this for artists as a seed, but tasteprofiles as the station seed works nicely as well :-)