I have a bunch of credits and in the past I've used them to buy myself 2 years of free CC, but $31 is cheap to me considering how much time I spend on here.
I'll use the TeeGee model
1. It's open to any freemium member who has been here for a minimum of 1 year (well ill waive this depending on the situation)
2. They must play games regularly (yes, I understand its a 4 game limit so game count will be lower)
3. Must NOT have had premium previously
4. Want to play more games.
I have enough credits to give out 3 3 month premiums