Coinstar deal gives an extra $5 in Amazon MP3s
The free MP3 bonus comes via e-mail a few weeks after you redeem your initial gift card. You will get a $1 bonus for every $5 you enter into your Amazon.com account in May 2010. You must use the bonus by June 30. Find a Coinstar near you.
Caveats: redeem your initial Amazon PM3 gift card by May 31 at 11:59 PM PST. Max bonus is $5. If you have not received your code by June 4, contact Amazon. Read the official rules here.