When I’m listening to music with Spotify-App on my smartphone, the tracks I’m listening to are shown automatically on this webpage in the sidebar. This is called scrobbling: it puts the songs to last.fm and then on this page. And this scrobbling didn’t work for more than a month now. Logging out and logging in on my smartphone solved this problem. 😉 So easy, but you have to do it. Have a nice day!