In the U.S., "Halo 3" sold 3.3 million copies in its first 12 days on sale, increasing to 3.7 million copies by November 15, 2007. Reuters UK estimated that "Halo 3" may have sold up to 5.2 million copies worldwide in the first two weeks after launch. By November 30, 2007, "Halo 3" had sold 5million copies worldwide, and as of that point, was the best-selling video game of 2007 in the U.S., even though the game is only available on one console. On January 3, 2008, Microsoft announced that "Halo 3" had sold copies. The game drew over a million Xbox Live members to play online in the first 20 hours, making it the biggest day for Xbox Live gaming in history. The game returned to the top 20 sales charts more than a year after its release in February 2009; Gamasutra reported that the boost might have been due to the release of "Halo Wars". According to Microsoft, "Halo 3" had sold 14.5 million copies . The game was also the best-selling video game of 2007 in the U.S.