You can check that same page to see your progress on the number of friends that have signed up and they will send you an e-mail when you have earned the $20.00 gift card!
This offer is totally legit – they have done similar promotions and always send out the promised prizes!
So hurry and sign up and refer your 3 friends! (And they can refer 3 friends and get one also!) You have until tonight to get it done!