In all honesty there is a very good chance of this going very wrong.
It is an MMO MMO's can never go wrong. Case in point SWG did everything under the sun to destroy their game in fact it was the biggest greatest game to failure game in the history of mmo's and it is still up and running LOL. They always will compensate somewhere. The initial paying for the game gets them in the black from there on out all the $15 does is go in their pockets and a little bit of staff and they probably own their own servers.