20 years ago I worked for a major gasoline refiner in Canada, who supplied the gasoline for all of the gas stations in Toronto. Esso, Shell, BP, Petro-Canada, Sunoco - all bought their gas from the same refinery. The whole WORLD is branding.
I think this finally hit me when I saw on display a tiny bottle of high-end "high performance surfer sunscreen" for $35, complete with beautiful packaging and a poster with attractive models.
You can still find this in small communities. I get my gas from a small community because it's cheaper on that side of the border. There's like 5-6 gas stations and one supply truck company. The locals all know to buy from the cheapest one and yet the Shell, Chevron, and others are still in business.