 On September 24, 2009, Valve announced that almost 3 million copies of the game had been sold.On May 10, 2011, Doug Lombardi mentioned that the game and its sequel have each sold 3 million copies on the Xbox 360.On August 11, 2011, in a phone interview with Giant Bomb, Chet Faliszek said that the series has sold over 11 million units in total.