Will launch with 2 million tracks available.

During Napster's first quarter earnings call Aug. 3, the company's CEO, Chris Gorog, revealed that its full song mobile music download service will go live next week with southeastern regional carrier SunCom. The store will launch with 2 million tracks available for download, more than both the Verizon and Sprint music services combined.

Gorog said the launch will be supported by and "extensive" marketing and advertising campaign including TV, print and radio.

It would be the first mobile music download service offered by a third-party brand and not directly from a wireless carrier.

During the earnings call, Napster positioned mobile music as its next area of growth. Piper Jaffray analyst Gene Munster said that targeting mobile devices with its service will increase Napster's available market ten-fold over the existing base of Windows-powered MP3 players today.

Napster also expects its mobile initiative to take root in Japan, where it has an alliance with mobile operator NTT DoCoMo. In addition to holding a controlling interest in Napster's Japanese joint venture partner, Tower Record's Japan, the carrier plans to introduce mobile devices that support Microsoft's Windows Media Audio technology—effectively making all such phones compatible with the Napster To Go service.