Silly Amazon. There you go again, giving away stuff again. Granted, this is digital stuff, and therefore may not actually exist, but it’s definitely free.
Go here and follow the instructions (hint: you must have a facebook account). Share your current favorite song and redeem your free MP3 credits.
You must redeem the credits by 11:59pm PST May 24th 2012. Blast, there had to be a catch.