Activision has announced that the Guitar Hero franchise has set an industry record by generating over US$ 1 billion in North American retail sales over a span of 26 months according to the data gathered by the NPD Group.

If you've been keeping up, this shouldn't come as a big surprise considering the success of Guitar Hero III: Legends of Rock (Xbox 360, Wii, PS2, PS3, PC), which was a key factor in the NPD Group's naming of Activision as the number one publisher in the U.S. in 2007.

The Guitar Hero franchise has sold more than 14 million copies since the first game hit the market back in 2005. In addition, Activision has given word that users have downloaded over five million songs since downloadable content became available.

As expected, Activision is very pleased with this turn of events. So before we go, we'll leave you with a few words from the company's President and Chief Executive Officer Michael Griffith who shared a few of his thoughts on the franchise and its success:

Guitar Hero is one of the biggest brands and one of the most powerful distribution platforms in all of entertainment today. Guitar Hero’s popularity with broad audiences is a confirmation that video games have become a true mass medium.