1. Make sure you have the latest version of their app: learn more about how to pay with OpenTable [opentable.com] (available iOS and Android).
2. Make a reservation and dine between June 2 and June 8 at a restaurant that accepts OpenTable mobile payments [opentable.com].
3. Add the promo code when prompted to view your check in the app. (You can only use it once!)
4. Savor your $20 credit toward your bill.