MTV parent company Viacom is brimming with joy these days over Harmonix's popular music and rhythm game Rock Band (Xbox 360, PlayStation 3, Wii). Its Media Networks division has experienced significant growth because of how well the title is doing in the market.

Viacom reports that since Rock Band's release late last year, three million bundled units have been shipped and over ten million songs have been downloaded from the game's music store. This spurred a 16 percent addition in revenue for Viacom, translating to some US$ 2.02 billion in sales.

An integral part of this success, Viacom says, is the update that gave Rock band an in-game music store. Four million songs have been downloaded since the March update, suggesting that easy access to the music store has encouraged players to shell out more for fresh tracks.

Viacom sees Rock Band as a long-term franchise which will reward the firm with more ventures. The MTV parent says it expects to see more good results when Rock Band hits the Nintendo Wii game console and debuts in Europe.