Around a year ago Activision announced that the Guitar Hero franchise had reached over $1 billion in North American revenues in just over two years.

Now the company has announced that just one game in the franchise, Guitar Hero III: Legends of Rock, has become the first game ever to generate $1 billion in sales alone.

Activision's CEO Mike Griffith told of the milestone during his keynote speech at CES. He also noted the positive affect Guitar Hero was having on the music industry itself, noting that Aerosmith sold over three times as many of its last studio album during the first week Guitar Hero: Aerosmith was released.

He also cited Nielsen SoundScan data that showed those artists who had allowed their music to be playable in Guitar Hero had seen download sales of their songs increase by 15-843%

"Music has a history of evolving through technology and we are at the beginning of the latest chapter in that story", he said.

"Movies, recorded music and TV - these are all stagnating or contracting entertainment sectors. Video games are poised to eclipse all other forms of entertainment in the decade ahead".

Speaking of the new Guitar Hero, Griffith praised the user-generated aspect of World Tour, noting that a total of 141,000 songs had been posted so far - 25,000 of those in the first 10 days.

There have also been 21 million user-song downloads, as well as 600,000 members joined up to the Guitar Hero community site.