I use these reusable coupons for motivation in the classroom. You could sell them in a "class store" or you can give them away in the class for outstanding effort, participation or any other reason you can think of that motivates your students.
This coupon entitles my students to receive a snickers bar. I use the minis or the small snack ones. I usually keep it in the "candy vault" in my room.
I had 6th graders and they LOVED the coupons!