Right now you can get a FREE $1 Amazon MP3 Credit when you download a FREE qualifying app from Amazon's Appstore for your android device or Kindle Fire. Qualifying apps have a message under the product description that says 'Get a $1 MP3 Credit.' You'll get an email confirming your FREE $1 MP3 Credit has been applied to your Amazon account. Limit one credit per customer.
Thanks, Common Sense with Money!