It's generational. I grew up with Clarence Birdseye commercials so I immediately knew who they were talking about from the article title. Who says you can't learn anything from TV?
Although I'm probably of the right generation I don't remember these. I learned who he was a few years ago when a friend of mine (I think) read a biography about him; he was apparently a pretty interesting character. And he came up again in the context of research for a book I was writing.