Spotify recently announced a major milestone: the music streaming service hit 10 million paying subscribers and now has more than 40 million active users across 56 markets worldwide. Since Spotify launched in 2008, more than 12 billion hours of music have been streamed. The most streamed artist? Eminem. (Rihanna is the most streamed female artist.) The most streamed song? Avicii’s “Wake Me Up.” Spotify is doing more than promoting artists’ music, however – it is amplifying their brands. David Guetta, the most followed artist on Spotify, has more than 5 million followers. …