Via Amazon:  

To get you started with Cloud Drive and Cloud Player, we're offering 23 great albums for $3.99 or less from our favorite record labels, including Universal, SonyRed, and EMI. Save these albums to Cloud Drive once your purchase is complete so you can enjoy them in Cloud Player wherever you are.

All new Amazon MP3 purchases saved to Cloud Drive are stored for free and do not count against your storage quota. We’ve started all customers off with 5 GB of Cloud Drive storage to upload more of your music, photos, and videos. Plus, when you purchase any MP3 album, including these, we’ll automatically upgrade you to the 20 GB Cloud Drive plan for free for a year.

Check it out:  Amazon Cloud Player Promo