Have you ever wondered why a coupon's legal fine print states, "cash value 1/20 cent" or "cash value 1/100 cent?"
The answer dates back to the days of the Great Depression. During that time, food was rationed through the use of food stamps. Greedy merchants took advantage of the situation by raising the price of goods, thereby inflating the value of stamp books. As a result, some state governments stepped in and, to make things fair, declared that all stamps and anything else used to decrease the price of a product (including coupons), should have a common value. In some states, these laws remain in effect today. Therefore, to avoid having to print multiple versions of the same coupon, marketers simply include the "1/20th cent" or "1/100th” language on all their coupons.
-Source “Coupon Fast Facts”, Coupon Info Now