Adserver wasn't Google but Tribal. An US company with a localized page behind the ad (games), for example.
Apparently some US-companies checked that this internet has no real borders. So be patient with us non-US people :) (just kidding).
For "virtual goods" a company shouldn't care where buyers are located. To deliver a fridge or a car to a customer on the other end of the world is a bit more difficult.