Amazon is offering you $3 in music credit to spend on any songs or albums at Amazon MP3. This is a credit, not a coupon. There aren't any catches or minimums, so you could just go there and buy 3 songs (at .99 each) for FREE!
Here's the link you'll need: FREE $3 in Music!
Promotional offer is valid from November 22, 2010 12:00 AM PST through November 29, 2010 11:59 PM PST. You must redeem the credit by November 29, 2010 11:59 PM PST. Other details are at the link above.