We have Poring ball but due to the fact that we have a lot of players playing Poring Ball, we can't give out a lot of coupons. We get a certain amount a week. If we exceed it, we would flood the server with coupons. Just think of this, usually we get 30 players on Poring Ball a side. If we give 10 coupons to each of them, we gave out 300. Quite a lot in a short time right? Which is why we cannot exceed the amount. Although the idea of making each event having a certain amount of coupons for each win is great. It personally depends on the GM themselves.