Amazon.com & Coinstar are doing a little bit of cross promotion for the month of May.
Here's How It Works:
1. Unload change. During the month of May, exchange at least $5 in coins for an Amazon MP3-branded Gift Card code at a Coinstar location near you.
2. Download music. Return to this page and enter your gift card code below by May 31, 2010 (11:59 PM PDT). Amazon MP3-branded Gift Cards are good for MP3s or millions of other items at Amazon.com.
3. Receive a bonus code by e-mail for Amazon MP3 music downloads worth $1 for every $5 in Amazon MP3-branded Gift Card codes you redeemed, up to $5 in bonus code value. Your e-mail will also include instructions on how to redeem your bonus code value.
For more info click here.