music being used is opt-out, revenue sharing is opt-in, that to me explains all about their ethos and how they run the service. It would not be at all difficult for them to go legitimate like Spotify with regards to technology and number of employees needed, but it would kill their business because they
can't operate "legitimately" like Spotify, that's not their business model.
Also I would eat my hat if you have a license that allows you to redistribute music you "purchased", I'd be even more surprised if that license allowed you to grant streaming rights to a third party. The license terms for an itunes purchase are extremely limited.