If they only know how to find cheaper transaction rates online then maybe, they already applied for a merchant account. Anybody would just stop by the gas station and gas up but, because of the inconvenience, some customers would just go and find another gas station. That's just easy for to do. Of course, establishments will lose their customers easy if they do not accept cards.
How about you? Do you own a business? You should not neglect this important transaction from the costumers. Your sales will improve if you accept cards. Do not just rely on cash payments. Just make a comparison and find the best credit card processing online.