Quote Originally Posted by Amberion View Post
They went from 12mil to 9mil subs during Cataclysm. Not sure what numbers you are looking at.

Just check the first pic you posted. It clearly shows stagnation during WoTLK and decline during cataclysm.
The thing is, though, what you might be looking at as stagnation might actually just be the hypothetical limit of the player base. The game was so popular that literally everyone had heard of it. They might be the only game in history to have come close to really getting every possible player that would ever be interested in playing the game within the regions of its release.