A ponzi scheme?

Dude, it's just a referrel campaign. You know how most sites/games will give you a commision/bonus/prize when you have friends who sign up using your link? Same deal here, basically..

A Ponzi scheme is when you earn money from* the people who sign up below you, until the pyramid collapses when no more new users/investors come onto the platform..

Reviewhunt is not using the people who sign up below you, they are just rewarding you for bringing them in.. They aren't taking away the earnings of the people who sign up under you.