$15 Gasback on Gasbuddy.

Pretty easy promo, pay $0.95 to sign up for Audible for a month and get $15 Gasback. Cancel Audible subscription, reap $14.05 profit. It's only running for another 24hrs or so. I found it in my inbox but you can also find it in the Gasbuddy app.

Edit: Don't cancel right away, takes 3-5 days for confirmation of subscription before you get the money loaded onto your Gasbuddy card.