Remember how cool it was when tony hawks and GTA first had licensed soundtracks?

(It was really cool.)

EDIT: Oh, apparently you can only build your apps into spotify, not build spotify into your apps. Boo!

EDIT2: Or maybe you can. It's not very clear. But that would definitely be an excellent market for this, allowing indie browser or mobile game devs to license music easily through an intermediary. Or maybe that's already an easy process?