By the way the highest cost of a successfull MMO isn't the servers or the people needed to write the continual expansions.
It's actually the bandwidth cost for the game and the customer support costs ( Blizzard has over 500 ppls working on customer support just for the US and you don't want to know about their bandwith costs....).
The line coming out of the server building isn't your typical DSL line, at the level of Blizzard it's custom state of the art shit ( because the nerds really go crazy when their servers go down even a few minutes, I know I was one of them, typically if the server crash, players crash the forums a few minutes later by checking for updates and then all the gaming sites related to wow start to be real slow as the wow players start all surfing at the same time while waiting for the game to go back up...)
As for comparing with Free to play MMORPGS, lets take the example of LOTR online
They claim to have increased their revenue by a factor of 3 when they went free to play. Except guess how they make money ?
The game is free to play but they charge 15$ a month for VIP pass to get access to some of the more interesting content in the game. So much for free to play..................
PS3-Xbox360 gap : 1.5 millions and going up in PS3 favor !
PS3-Wii gap : 20 millions and going down !
