Spotify has had a very successful entrance to America, adding 500,000 users since integrating with Facebook two months ago. A new academic paper reveals that Spotify relies heavily on its friends, namely its users, to help stream tracks to one another and avoid hiccups in the playback.
We had always assumed that Spotify used its own servers to send the data we request in the form of a new Das Racist track. And we knew that Spotify cached some of our favorite tracks for offline play. But according to Spotify – Large Scale, Low Latency, P2P Music-on-Demand Streaming, a paper by Gunnar Kreitz and Fredrik Niemelä, only 8.8 percent of Spotify streams come from the company’s servers. The rest comes from local cache (55.4%) and an ingenuous peer-2-peer network (35.8%)
Since more than 60 percent of Spotify plays are from album’s, the service can predict what songs are coming up. Add to that the fact that 88 percent of song requests are for the most popular 12 percent of tracks and you can see that there is a big swathe of activity that Spotify knows will make up the bulk of its usage.
When talking about music services, the big labels contrast paid services like Spotify with the BitTorrent networks that form the backbone of internet piracy. But the two services actually work in a similar way. When a user streams a track, Spotify searches among its peers to find as many as 60 different users who can help stream the track.
Typically Spotify will only have to rely on its servers to stream the first 15 seconds of a track. After that the peer-2-peer network takes over. The exception to this is mobile streaming, where Spotify has been much less reliable in our experience.
It’s fascinating to think that Spotify has a built-in network effect on both a social and a functional level. As the service continues to expand, it will be able to rely on a larger user base and offer smoother playback. Of course users’ taste can vary pretty widely around the world, so a new group of users in the United States may not have a ton of overlap with the top of the pops in Europe.