To be honest, speaking from an economic standpoint, if they did advertise in their games, I doubt they'd actually lower their price. The current price for a new video / PC game is pretty standard, and after millions in marketing dollars, they've figured out the price equalibrium somewhere around $50 for a well designed, professionally created new game. If they were to advertise, we may see the quality of the games rise, but we'd likely not see a dip in price.