MTV-owned Harmonix, developer of Rock Band and the original creators of the Guitar Hero franchise, has the potential to earn an additional $208.7 million from parent company Viacom thanks to its success over the last year.

According to a recent 10-K filed with the Securities and Exchange Commission (SEC) by Viacom, "To the extent financial results exceed specific contractual targets against a defined gross profit metric through 2008, former Harmonix shareholders will be eligible for incremental earn-out payments with respect to the years ended December 31, 2007 and December 31, 2008. At December 31, 2007, a liability of $208.7 million has been recorded in Other liabilities on the Consolidated Balance Sheet for the expected earn-out payment. We expect to have a final payment with respect to the year ended December 31, 2008 done in 2009."

[Clarification: We originally stated that Harmonix's shareholders had already received the payment of over $208 million, but technically this is not correct. Shareholders are eligible to receive this money over two years if Rock Band remains profitable.]

MTV originally acquired Harmonix in September 2006 for $175 million.

Rock Band has yet to reach Guitar Hero-like sales numbers, but considering the package is more expensive it's done quite well. The game has sold over one million units and gamers have downloaded over 2.5 million songs to date.