As seen on Facebook:
Amazon MP3
If you heard something you like on the Billboard Music Awards, get this $2 credit towards MP3s and buy it.
Upon completion of the "Share & Claim" action, a $2 MP3 credit will be automatically applied to your Amazon account. Promotional credits must be redeemed by 11:59 PM PST on May 24, 2012. Amazon MP3 music is available to customers located and with billing addresses in the United States. You must have an Amazon.com account and accept the Amazon MP3 Service Terms of Use to redeem your credit. Limit one promotional credit per customer.
http://www.amazon.com/gp/socialmedia/promotions/anc-mp3