There are individules that are brand loyal and will pay the higher price at a Chevron or a Shell regardless. Also works well if you do not have a Safeway Station in your area or while on the road with family on vacation with no Safeway station nearby. This is a positive
Combine this with the fact that Chevron and Texaco are nearly always priced 15-20 cents higher than most gas AND SWY grocery prices are 10-15% higher than some of their competitors.....not a good deal!
Shell is one of the highest priced gasolines, so there isn't a lot of savings there either. I redeem my rewards at Safeway stations where the price is already among the lowest, and the rewards bring it even lower. Sometimes up to 90 cents [er gallon. No, I don't have a Safeway station close by, but in my travels to California, it sure helps.