2 open slots a day 
there are 17000 members, and with this third game open only 1500 spaces!
No, there
has been 17,000 members. Not presently are. Over the course of several years
many people come and go.
I'm quite certain that sami knows precisely how many currently paying players he's got. And he's not in the business of turning paying customers away. But if he wants to be due to resource constraints, that's his business. Remember, every game-world created means more time that sami has to do deal with managing each world dealing with PMs, complaints, bug issues, etc; and less time upgrading the game. And as someone waiting for long-awaited updates to AWS, I, for one, would prefer he spends more time working on the software and less time managing the individual worlds.