Speaking at the World Mobile Confgress in Barcelona, Daniel Ek said that the average Spotify user has 15,000 tracks lined up across all their playlists – a huge number, showing a really deep engagement with the platform from its users. OK, adding tracks to playlists doesn’t cost anything, but it takes time and effort to build them… Spotify hasn’t had any problems gaining users, or with the enjoyment those users get out of the service, but they’re still struggling to get more of their users signed up to the premum subscription service. As it stands, their users aren’t making them enough money per head to make a fully open launch an option, and Spotify has had to limit their intake of new customers to stop their streaming and royalty costs down. Advertising revenues are rising though, and as revenues and subscription customers increase so will the long term viability of the platform. They must be champing at the bit to launch in the US, as their competitor MOG is making good inroads into the American market.