Start at Bronze 10%
You'll earn 10% of any revenue collected by users that sign up with your coupon code forever. 

Earn $500, go to Silver 15%

Once you earn $500, you'll be automatically graduated to Silver where you will earn 15% of all future users revenues forever. 

Earn $1,000, go to Gold 20%

Once you earn $1,000, you'll be automatically graduated to Gold where you will earn 20% of all future uders revenues forever.