(Video Link)
In the 1950s, before the Muppets, Jim Henson produced these commercials for Wilkins Coffee. They are, uh, very blunt. To summarize, the message is "Buy our coffee, or we'll kill you." The brand appears to be defunct. Read more about Henson's early puppetry at Network Awesome. Link -via Boing Boing
I also like the muppetness... 50s style.
http://networkawesome.com/show/collection-the-commercials-of-jim-henson/
Here are a few more...
http://www.foodiggity.com/7-of-the-best-food-moments-in-muppet-history/