Doesn't keep the annoying young ones out during winter and summer break. There's another load of annoying, disrespectful Japanese youngsters running rampant through the game at the moment, or at least this is what the complaints are saying lately.
It was the same in another p2p game I played a while back. It is pay, but when you have lots of free time, and you're a kid, and you whine and beg your parents to pay for you...