The growing trend of increasing digital sales and slumping sales of physical CD’s looks to continue in 2008. Today Interscope Records announced that 17-year-old Soulja Boy Tell’em eclipsed the 3 million sales mark for downloads of a digital song with his single “Crank That.” The single was number one on Billboard Magazine’s “Hot 100” chart for seven weeks, yet according to Nielsen SoundScan, the actual album has only sold 658,000 copies.

The news comes just days after Flo-Rida broke the record for the most digital downloads in one week by selling 470,000 copies of the single “Low.” Nielsen SoundScan also reports that total downloads topped 6.7 million last week, while overall CD sales dropped by 16 percent in 2007. For his part, Soulja Boy (Born DeAndre Cortez Way) seems to be taking the support, digital or otherwise, in stride.

“I can’t thank my fans enough,” said Soulja Boy in a statement released from his label, Collipark Music/Interscope Records. “Without them all of this wouldn’t have been possible. The support they give me is beyond incredible. I have so many Soulja Boy Tell’em projects ready and I will continue to give them what they need in 2008. Yuuuuaaaa!”

The song “Crank That” and its accompanying dance has been criticized for its simple chorus, and some critics have panned Soulja Boy for a lack of originality, among other things. The rapper was also forced to defend his song when a rumor began that a line from the song stating “Superman dat ho,” had sexual connotations [click HERE for the link]. Nevertheless, the song continued to gain popularity, and has sold the highest amount of digital downloads since Billboard began tracking the statistic in 2003. The previous record holders were Gwen Stefani, with