Call of Duty 2 was one of the first games I tried out on the Xbox 360, and so it is not surprise to me that they have now sold ovr a million copies for the Xbox 360 in the USA alone.
No doubt Activision is happy to have it called the best FPS that the Xbox 360 has.
There is a free demo of the game in the marketplace, and it is pretty enjoyable, though relatively simple. Check it out, and you will probably want to be part of the second million to buy the game.
Source: 360Monster