Virtually any kind of advertising can act as a coupon. Include a coupon to clip on your fliers. Staple a pad of coupons to your small sign. You can even make a display ad look like a coupon. Some Internet entrepreneurs have issued e-mail coupons.
Some industries use coupons extensively.
It's hard to sell a pizza without a coupon. If your line of business does not normally use coupons, consider your situation a real opportunity. My neighbor, a family doctor, promoted his new location by offering a coupon discount for the first visit to his office.