Does anyone know how this is charged? They try to explain it on their site but it is confusing as heck. Assuming you have your tv ad already to go how are you charged? Something about putting down your maximum cost per thousand impressions?

And then Google says they'll track the views your website gets from the commercial. How is this even possible? What if you get views from some other source? Is google just looking at the time the commercial runs and then looking at your hits?