At one time there was no TV, only radio. Tom Mix, the Lone Ranger, the Cisco Kid, Captain Marvel and a few other kid programs were on the radio. They advertised cereal, or chocolate drinks etc. For only .25 cents, along with a box top of the advertised cereal a kid could get the special ring, which was included in the story line of each program. I remember one program that had a special decoder built into the ring. During that weeks story, the decoder would be used to solve the case, then at the end of the program they would broadcast a code for all the kids had purchased the special decoder ring. I took a proper box top, taped a quarter to it, along with my return address and sent it off to some place in Battlecreek, Michigan. My one size fits all ring finally arrived, and I had my ear to the radio and copied the ending secret message. The decoded message said something like, "Drink more Ovaltine." I was not a happy camper.