Thank you for posting this link. I read through terms and condition and in the past many of these types of promotion excluded Gas Stations ran by big box warehouses such as Costco. I did see that language in their Category FAQ.
"These merchants operate warehouse-style retail stores, sell in bulk, and concentrate on price appeal. Merchants sell a full range of household goods and merchandise, groceries, furniture, electronics, appliances, and auto supplies. These merchants may or may not have membership requirements. Gas, fuel, wholesale specialty service purchases such as travel, insurance, cell phone and home improvement will not qualify in this category. "