A "plug" is a small banner advertisement that can be displayed on a plugboard. You can put together a plug on your own if you have computer skills.
A special thanks to BittyMoose.etsy.com for introducing the plugboard to Etsy. BittyMoose will make an animated plug (88 x 31) for you for $5.
I've put a plugboard on this blog, so feel free to plug in. Visit our fellow advertisers by clicking on their banners.