For me it's impossible to monetize it yet. I'm located in The Netherlands and I've got to deal with a RIAA similar organisation called Buma/Stemra. If I monitize it I've to pay large amounts of license costs (I'm just a poor medicine student). Since a half year Buma signed a deal with Youtube which finally allows me to embed (music) videos for free, as long as I don't monitize it. Last.fm API is free, but they want to see money if you're getting rich by using their API. Youtube doesn't seams to be a problem. Youtube doesn't seams to be a problem.

tl;dr Not at this moment. Dutch RIAA problems if I do. Last.fm wants money if you are getting rich.