Valve, widely known for creating the Half Life franchise and Steam, has announced they have sold over two million copies of Left 4 Dead 2.  So far, sales for the title have already doubled the original. Valve is crediting the “Black Friday” promotions during the game’s second week of availability for this huge surge in numbers.

Doug Lombardi, Vice President of Marketing at Valve commented on this saying:

Meanwhile the title has already been played by over 1 million Xbox LIVE Gold account holders, and news regarding L4D2 DLC 1 is coming very soon.