You mean you remember S&H Green Stamps?
Yes I do.
Between 1966-69 I was old enough to work at my father service station on a busy highway between Brentwood and Antioch, California if I remember, this is almond orchard country near the San Joaquin Delta.
I think the gas was .19 for regular, .21 for premium and we also had ethyl which I think was higher than premium, 100 octane stuff at .24 a gallon or 9/10ths.
I think the station was a Flying A with the pegasus horse, I was but 11 years old, my dad played a good trick on me when he asked me to check the coolant on a volkswagon, and he made money telling customers that the air in the tires needed to be changed, his brother my uncle was so dumb he thought when a tire was 32psi it was 32 pounds heavier.
We had the large glass coke bottle style of oil available, a one bay stall with an air lift, tire repair equipment and a small stock of headlights, bulbs, fan belts and hoses. Back then things were pretty basic. We had both Blue Chip and S&H Green stamps, the latter seemed to be more sought after, a few years later when we again had a station in San Jose when IT was still orchards we advertised 10X blue chip stamps with fillup, well there was a nearby California Hihway patrol office and they had those great big patrol cars with a 30 gallon tank I think and they would come to our station jut for the stamps, the machine was like an old rotary phone, you dialed in the amount and it rolled out like a paper towel, these officers were getting a LOT of stamps.
I think the Blue Chip or S&H stamps idea would or could make a comeback successfully.