You have to refer 10 people to the program, and they have to complete an "offer"
The offer I completed was some discount club that cost a dollar for a 30 day trial, you can't cancel for 7 days. I cancelled after that and I have credit for my completed "offer". If you explain to your referrers which you think are the easiest "offers" to complete it's pretty easy to get them filled up.
So far I've referred 6 people who have completed their requirements. So I'm getting close.
Here's my link if you want