Stop reading this post. If you came here to find a formula to produce the game of your dreams, then you can quit right here. As a matter of fact, you can quit reading all such articles on how to make game X. They won't get you where you want to go.
Every howto you read was written by someone who did not need a howto. If they had used one, there wouldn't have been a need to write one in the first place. They gained the knowledge they needed to do what they do by other means and most probably have a deeper knowledge of their subject because of that.
And honestly, we have enough MMOs. Like, way too many.