You can have your own MMO online and make some money out of it if you come up with a good idea. Multiverse might just be the solution you need if you are thinking on those lines.

Multiverse, a startup company, makes MMOs for a fraction of what it takes to make one. It also offers the alternative of enabling any IP owner to create an MMO game for just $10,000 and in about half of the usual time to market. It uses common technology with open standards that are expandable. What more, developers also may host their own games and use Multiverse's tools to handle subscriptions and billing.
So when are we going to see your answer to World of Warcraft?