Country sensation Taylor Swift is on pace for digital music sales history as her latest single is currently projected to move more than 600,000 copies in its first week of availability.  Released Monday, August 13th, "We Are Never Ever Getting Back Together" is the first track from Swift's upcoming fourth studio effort, "Red," which arrives in stores October 22nd.  If prognosticators' estimates are accurate, the song's first-week sales would be the second-highest digital sales week for any song ever and the biggest for a female artist.  The largest sales week ever was for Flo Rida's "Right Round," which sold 636,000 copies in its first week in late February 2009, while Ke$ha's "Tik Tok" is the only single from a female artist to move more than 600,000, reaching 610,000 in Jan. 2010.