I’ll WAG. Convenience stores, that usually sell gas, have used milk as a loss leader to get people to shop in their store. While everything else is overpriced compared to the grocery store, milk is usually pretty cheap. It stands to reason that they are trying to buy at the absolute bottom price. That probably means that the milk they are buying is near the expiration date. It’s milk that the dairy has to rid themselves of before they have to dispose of it. Compare the expiration dates to the dates on the milk in the supermarket. I’ll let you do the footwork. Tell us what you find.