They are as old as radio itself. And they were one of the first electronic mediums next to lighted signs. They are radio commercials. On August 28th, 1922, the first one ever ran on WEAF in New York City! And there was only one reference to a big sale! :)

It actually was an ad for THE QUEENSBORO REALTY CO. and it lasted 10 minutes! The spot cost them a reported $100. Now days 30 or 60 second commercials are the norm. It was a different time then, Babe Ruth starred for the Yankees, candy bars were a nickel, and Joan Rivers had just gotten her start on stage! Ha!

Here's classic 1970's radio commercials!