If you haven't already heard of this by now, Amazon is giving away a $2 free credit for their MP3 store. Just click on the link and press the button to receive your code and apply it to your account.
If you are on Facebook, you can download Skrillex's remix from EA Games' upcoming sci-fe shooter Syndicate by liking the page.
If you like Skrillex, you can also get the First EP Album free at http://www.bloodcompany.net/skrillexep/
(FREE with Amazon Prime!)