putting ads on a facebook game?

Im about to finish a web browser game Im planning to publish on facebook, I want to start now with putting ads on my game to make me a millionaire (lol) the thing is I have no idea where to start... as far as I know there are ad networks i can subscribe to like admob... but isn't admob for mobile games only? ... I dont know, Im so lost, how do you put ads on a browser game anyway? is it as simple as adding a gameobject with the ads in it? Any help of where to start will be greatly appreciated.