Rock Band: 10m Units Shipped Worldwide

The Rock Band franchise has sold millions, but according to MTV Games parent Viacom, the series fell short of expectations for the fourth quarter ended in December.

Viacom CFO Tom Dooley said in a Thursday earnings call that Rock Band 2 sold nearly 2 million units ("hardware, software and bundles") since its debut in September 2008 across all platforms.

But a challenging retail environment kept sales of the sequel below Viacom’s projections, Dooley said.