After a slow start in 2011 to ramp up premium users, Spotify reached five million subscribers in 2012, with one million of those in the U.S., putting it at a value of $3 billion. The music streaming and discovery service has annoyed some acts and copyrights holders like the Black Keys or holdout Rihanna with its royalties structure, but other acts like Metallica have embraced posting its music at long last to its search archive. Volvo announced it'd be installing Spotify in its cars at a later date. Users share playlists and new artists easily on Facebook, and the service provides music fans with to-the-minute information on the most-streamed and most-viral songs.