On top of that, players have purchased over 40 million paid individual song downloads. Over 600 songs are available, selling for $6.25 for three-song bundles or $1.99 per individual song.
Rock Band 2 launched in North America last year for $189.99 on PS3, Xbox 360 and Wii.
Viacom, which owns Harmonix parent MTV Games, said the Rock Band franchise had shipped 10 million units since the series' November 2007 debut.
According to NPD, Rock Band was the number one title of 2008 by revenues.
Competitor Activision announced in January that 2007's Guitar Hero III--on its own--had surpassed $1 billion, although that figure is in total worldwide sales.