lol i use that site till the cows come home for everygame thats comes out. so many diff mirrors its just great ey.
games do not need the cd/dvd to play them. all they do is run a cd validation to check that u have a cd so that u must have bought the game. if files were loaded from a disc while ur playin it would slow down u game alot. downloading a game just gets u the cd image so u can install it then replace the executable (or other files sum times) to remove the cd validation check.