I keep hearing radio spots for this, and looked it up. Some people rave about it. Some warn that the money they'd banked, the savings you're supposed to see from each gas station purchase (and even some grocery stores), vanished abruptly, and they had no recourse. It looks like a lot of hassle even if it does work: You can't pay cash, you have to use a credit or debit card, have to scan your receipt and upload it, etc. I wonder how much personal info they'll want about you if you sign up. Anybody try it?