Gangstar has ads too, as does many free to to play games, the difference is they only pop up when you open the map or other menu options and it doesn't happen constantly. Sometimes when an ad tries to pop up it messes up and it just boots you out of the game. Randomly walking around and an ad pops up. Oh my cow are there a ton of ads!!!! I was messing around with the settings and before I even had a chance to look at the other options and an add pops up.
