There are two accounts that ship with most GFW Live games-one is a one-month prepaid gold subscription to Xbox Live!, the other an actual product key like most PC games have.
This is the latter. You can still probably play the game online and what not with a silver subscription, as one of the key differentiators between the 360 players and PC players on live is that Silver subs on the PC can still play games online (though there is usually good value for Gold membership for most of these games, notably multiplayer achievements and matchmaking/leaderboards).
