Pepsi and Amazon.com unveiled their long-expected digital music promotion, to kick off during a Super Bowl commercial starring Justin Timberlake.

The promotion, called Pepsi Stuff, is designed to introduce the new Amazon digital music service to the world. To date, Amazon has done very little marketing around the service, but is ramping up efforts now that it has secured content form all four major music labels.

The promotion begins Feb. 1, in which Pepsi will distribute 4 billion specially marked Pepsi packages -- including bottles, six-packs, etc. -- that let buyers collect points which are good for free music downloads on the Amazon.com service. Players "bank" their points at PepsiStuff.com, with five points good for one free song. The points are also redeemable for TV downloads, electronics gear, clothes, DVDs and CDs and other merchandise sold on Amazon, totaling $1 billion in prizes.

The Amazon digital music service, of course, contains no DRM protections, meaning songs acquired from the store can play on any digital music device.

While Universal Music Group has licensed its catalog for the Amazon service, fans redeeming Pepsi points as part of the promotion won't be able to download UMG songs, as the label is not participating. The other three labels, however are, along with a multitude of independent labels. UMG reportedly declined to join in due to concerns over how Amazon is compensating labels for the free tracks.

One of the criteria labels set for agreeing to Amazon's DRM-free service was for the company to back up the effort with a strong marketing campaign. Amazon's Super Bowl commercial introducing the campaign is the first such example. The commercial will be Timberlake’s first Super Bowl-related appearance since the infamous "wardrobe malfunction" in 2004.

The Pepsi Stuff promotion plants the Amazon music flag deep into Apple's territory. Apple four years ago first teamed with Pepsi on a similar free-track redemption program, and also promoted it with a Super Bowl ad. Amazon's gambit can be seen as an attempt to establish a new sheriff in town. It also introduces the concept of DRM-free music to a more mainstream audience.