Shop ‘N’ Save used to have a sinilar deal here with Go-Mart a while back. Twenty cents off/gal when you spent $100. They stopped because the mgr. of the supermarket said he didn’t see any increase in sales.
Safeway in California gives you 3 cents off a gallon if you have a Safeway Shopping card. Twenty cents a gallon off if you spend $100.
They still do that and I used Safeway as my gas station all the time when I was down there driving.