It's no surprise that coupons continue to be one of our most popular promotional tools - after all, we launched Woobox with coupons as our first app. Since then we've grown to include a much broader suite of promotional tools, but coupons remain popular. There are a wide variety of uses for coupons, from free offers to loyalty rewards, to feel-good perks. Check out these 6 effective coupon strategies that have proven successful time and time again: