In September of last year, Bobby Kotick, head of publisher Activision, stated that the famous gaming series Guitar Hero remained the most popular in its genre, outpacing sales of Rock Band from EA by six times.
According to Gamespot, citing official data from the research firm NPD, Guitar Hero World Tour outsells Rock Band 2 by exactly two to one.
Since going on sale, 3.4 million copies of Guitar Hero World Tour have been sold, while Rock Band 2 sales amounted to 1.7 million copies. As you can imagine, this refers only to North America.
It remains to be recalled that Rock Band 2 was released in the US on September 14 for Xbox 360 and on October 19 for PS3. The Wii version went on sale only on December 18. Guitar Hero World Tour was released simultaneously across versions for all consoles on October 26.