While Nielsen includes outlets such as Amazon (AMZN), Starbucks (SBUX), and Hot Topic (HOTT) in the non-traditional category, iTunes is clearly the standard-bearer -- it easily surpassed Wal-Mart (WMT) as the country’s top music retailer last year, and sold more than 6 billion songs in January 2009 alone.

While independent music retailers have solidified their position over the past 5 years, mass merchants such as Wal-Mart and Target (TGT) saw their market shares rise between 2001 and 2006 before falling in recent years. Starting with Target’s Spotlight Music Series in 2007, these megastores have sought to regain their footing by making exclusive retail agreements with top talent.

Christina Aguilera, The Police, and Guns 'N' Roses have all released albums exclusively through Best Buy. Others have done so through Wal-Mart, including The Eagles -- whose album Long Road Out of Eden was 2007’s third-biggest-selling record -- and AC/DC,  whose Black Ice sold 780,000 copies in a single week. The albums were made available online and at independent retailers -- probably in part because the average 12-year-old has never actually heard of a “record store.”

Figures demonstrating how these exclusive partnerships compensate artists compared to traditional major-label distribution aren’t available. But one thing is certain: They provide those artists who have historically railed against their record labels – such as Prince and Pearl Jam, both of whom are going exclusively through Target -- some retail independence.

You may remember that Pearl Jam once sued Ticketmaster (TKTM) over unfair business practices. The band had been signed to Sony’s (SNE) family of labels for 18 years. But with their contract up, instead of signing with a new US label, Eddie Vedder & Co. established a consortium of partners and charged Target with distributing the album.

Thanks to moves like these, CDs are just on the endangered-species list -- they aren't extinct.

Yet.