I suppose that's one way of looking at it, and I certainly don't think you can go wrong buying fuel (after all, I believe just the opposite) but OTOH I can't help but wonder whether those extra $4 per fill up help pay for... extra advertising.
There's a Chevron station I know that is great to go to, because it's clean inside and out, the ice cream is always stocked fresh and they have those machines that grind coffee beans on the spot for each cup you buy. They also offer handy-wipes and funnels for fluids, and they're polite and cheerful. Great station.