There is a newer paper than the one described in the linked article available (http://www.csc.kth.se/~gkreitz/spotify-p2p11/ http://www.csc.kth.se/~gkreitz/spot

There is a newer paper than the one described in the linked article available (http://www.csc.kth.se/~gkreitz/spotify-p2p11/ http://www.csc.kth.se/~gkreitz/spotify-p2p11/) that has some interesting measurements on the network.