The Nielsen Company revealed the impact that a performance on the Sunday Results programme of the UK series X Factor had on digital download sales (online and mobile), online buzz and radio airplay for the special guest stars promoting a track.

2009 music purchases in the U.S. were up 2.1% over 2008 figures, marking the second year in a row that sales exceeded 1.5B units sold according to Nielsen SoundScan.

In its opening week, “I Dreamed a Dream,” the debut album from singing phenom Susan Boyle, topped the Billboard 200 album chart with sales of 701,000 copies according to Nielsen SoundScan, overtaking Eminem’s “Relapse” as the year’s best sales week for an album in the U.S.