http://www.playbutton.co/
I am so blown away by this idea. If you think its stupid, go to your nearest city and count how many hipsters/scenesters/punks are wearing pins.
they said we would have an unfair fun advantage
Pretty interesting way of promotion :) I wonder how would it cost. Personally, I prefer donation system or older way "download 128, buy FLAC" or something.
(english is not my native language, sorry for grammar.)
A better way to sell music: bandwidth metering.