Quite simply your friend tells us. We mark that down in our system and if they go ahead and purchase the sale is credited to you. 

We will create a credit notice in your account and it will be applied to your next invoice. 

Absolutely not, refer as many friends as you can think of and let them know that by using this program they will be giving you money as well. 

To be eligible for the referral program credit your friend must spend a minimum of $500. 

No you don't...but it would make more sense :) When you suggest a service it helps to have used that service yourself. Although, we certainly welcome any new clients you want to send our way.