Online role playing game making millions

Internet enable people to play games with many other people all over the world.  Worldofwarcraft.com made a popular role playing game called, World of Warcraft.  You can be different character and search for treasure and compete with other people.  It's making millions.

Problem:  Playing game can be boring because you are playing against the computer.
Idea/Solution:  Website + Role Playing Game + Millions of players all over the world playing + Monthly fee
Site:  http://Worldofwarcraft.com