Great to see you're using the gralats idea. I also like that you're using real prizes and stuff that can be won. Let's just hope that the in-game items and stuff that you can buy with the gralats are actually worth the money, and not just stuff that should be available to everyone to begin with.
There's definitely a right way and a wrong way of doing the pay thing... if you make people pay to access levels or fly in balloons then it's going to get ugly... if you let people buy special clothing items or experience boosters then it wouldn't be so bad.
Just remember that nobody wants to pay $30+ for yearly access PLUS extra money just to get more things that should come standard...
