Jiminy Cricket is no fool, so he endorses Sylvania tubes in this ad shown in the July 1940 issue of Radio Craft. It’s not a magazine ad, but instead a picture of a poster that shops could display. And just to be on the safe side, Jiminy strongly suggests that you should just go ahead and replace all of the tubes while you’re at it, even if they’re still good.

Also shown is a clever business card that probably won’t get thrown away immediately. It’s a disentanglement puzzle, the object of which is to remove the string from the tag without tearing or bending the tag or cutting the string. The photo here isn’t very clear, but it appears to be similar to the puzzle shown in this video.

Those who can’t figure out the puzzle are directed to their nearest Sylvania dealer, where the owner will show how to solve the puzzle, and also solve any radio problems that you might have. And while you’re there, he just might sell you a complete set of tubes to replace the perfectly good ones in the radio at home.

In the past, in lieu of business cards, I’ve used things such as customized rulers, promotional calendars, and wooden nickels.  A puzzle made out of cardboard and string probably doesn’t have a lot of staying power, but it will probably get looked at.