Well that depends in my opinion. If your game makes enough to keep a single server populated (high pop in peek hours) and a development team in place, I'd consider it successful. Especially if you can keep the playerbase for a long period of time. They'll tell their friends about the game they're playing and ultimately drag more people into it.


So many people buy or sub to an mmorpg in its first month but never look at it again, it's important to keep the playerbase interested and hooked from the start when you're play 2 pay game. F2P customers will always return if they had a decent first experience.