^ because they're game sites. There's no point advertising penis enlargements in a dressupgames and games in a funeral site. If you wanna hit your target audience, wouldn't you advertise where they'd be? So if I was a gamer, where else would I be but at a gaming site? And if I'm there then perhaps I could be enticed to come here through an effective ad. If you're wandering why the game sites allow other games to advertise it's cause usually they don't have a choice. The advertisements bring in the money they need and as for the ads placed, they don't really have a choice over them. Plus if it's adsense, or something like it, it will advertise something related which in a gaming site would be -you guessed it- another gaming site. And that gaming site just has to put up with it, but as long as its good its members wont completely leave it and if they're still attending it then the site owners have no complaints there so they'd have no beef. Plus, other sites are forced to give said sites the same courtesy so while their players join the other games, the other games' players join this game and they're aaaaall happy and friendly and have fun parties where people get drunk and wake up the next morning with very sore heads and dead hookers.
At least that's what I think
