You got it right, the smaller ones have too buy it from somebody.
Another very good point, I at the moment, walk or hitchhike everywhere, (or bike but its broken at the moment) simply because I had too chose between driving a car, or going too university. Which I think is insane.
I'd say that was a very creative new attempt at the usual chain letter, But if people all used car pools and buses, rather then personal vehicles, that would take a HUGE dent out of the big companies pocket. It wouldn’t matter where you bought the gas, if one car was buying rather then 6, or even if everybody went in pairs, rather then there own car it would cut the gas company’s profits in half. They’d loose money fast, not too mention would hurt the environment too have less cars on the road any way. So it’s like killing 2 birds with one stone.