Microsoft has confirmed that Gears of War 3 has sold 3 million copies in its first week, with the franchise being the first Xbox 360 exclusive franchise to eclipse the $1 billion sales milestone. Microsoft also notes that the game has racked up over 50 perfect review scores.

Gears of War was the first killer app for Xbox 360, and the series has continued to contribute directly to the overall success of the platform ever since,” said Microsoft corporate vice president Phil Spencer. “Gears of War 3 kicked off the biggest Christmas period in Xbox history, setting the standard for the kind of amazing, action-packed experiences gamers should expect on Xbox 360 this year.”