And generally, the fact that distribution of original music is effectively a two-sided market business model (media) means music isn't worth as much until it is popular, so one method has been to give it away for free to get to that point (think demo CDs).

Spotify deserves a lot of credit for handling the mainstream content to an international user base. The business rules of serving which version of a song (two users who play the same song can be served different content because of licensing rules), accounting for the royalties to different publishers, etc... are hard enough to figure out.