When did Spotify abandon their original peer-to-peer architecture?[0]<p>[0]<a href="http:&#x2F;&#x2F;www.csc.kth.se&#x2F;~gkreitz&#x2F;spotify-p2p10&#x2F;spotify-p2p10.pdf" rel="nofollow">http:&#x2F;&#x2F;www.csc.kth.se&#x2F;~gkreitz&#x2F;spotify-p2p10&#x2F;spotify-p2p10.p...</a>