Get a Big Mac Burger for only 99 cents. Mobile Order Pay at participating McDonald's. According to Retail-Me-Not, they average savings per visit by one of their online coupon shoppers when they go to McDonalds.80. The fact is, you can find good McDonalds promotions published just about anywhere, from local newspapers and periodicals to online coupon sites and from Facebook to Internet coupon shoppers forums and message boards. Free Big Mac or Quarter Pounder with Cheese.