All you have to do is click here, name your favorite song of the moment and then share the information on your Facebook wall (you can always delete the post right after if you don’t want to continue using the app).
The credit will automatically be added to your Amazon account and you’ll be streaming free music before you know it.
Just be quick! You must use your credits by Thursday.
Note: Amazon MP3s can be streamed through iTunes. I’ve found that Amazon is often cheaper than iTunes and it’s become my go-to place to buy music, but I still keep track of all my files through iTunes.