Eighty years ago, WLS in Chicago wanted to remind its advertisers of its importance to agriculture by running this ad in the July 28, 1941, issue of Broadcasting. The station knew that many farmers had a radio in the barn and listened to the station while they worked, so it asked them to write in and join the Radio in the Barn Club.

2000 farmers in 14 states responded, demonstrating that American farmers had come to depend on radio for its business value.