Not only has the Guitar Hero videogame series surpassed $1 billion. Guitar Hero III: Legends of Rock itself has, GameDaily reports. It, too, reported on Activision CEO Mike Griffith's keynote at the giant CES show in Las Vegas last week, citing his statement that "the videogame industry has had a profound effect on other entertainment sectors, and that Guitar Hero in particular has been hugely important to the music industry." Evidence: Griffith cited Nielsen data showing that "artists whose music was playable in Guitar Hero had seen download sales increase 15-843%." The newest Guitar Hero game allows players to compose their own songs. Activision data claims that in the game's first 10 days, 141,000 songs were posted by players, and the Guitar Hero community site has more than 600,000 members. "To date, there have been 21 million user-song downloads."