I don't know who put this rumour out but in an (mmorpg) online game a player consumes ~2kb/s (0.5 up, 1.5 down) so 250 players would mean 500kb/s traffic - standard servers support 10 to 1000 mb/s traffic.
And smaller online games don't use zones at least they are not running on different servers! So a good server can handle about 2000 Players in an mmorpg without any trouble.
I even know some examples where the game-server and the web-server are the same physical machine.

sorry for offtopic...