Author William Peter Blatty once won $10,000 on this show. When Groucho Marx asked what he planned to do with the money, he said he planned to take some time off to "work on a novel." The result was the novel "The Exorcist", published in 1971 and adapted as The Exorcist (1973) two years later.
George Fenneman, Groucho Marx's announcer on the show, was once asked if Groucho ever embarrassed him on the air. "Each and every show," Fenneman replied.
When the game show came to television, Groucho Marx was asked to wear his traditional greasepaint mustache. He declined and decided to grow a real one instead, which he wore for the rest of his life.
It is part of Hollywood legend that one of the source recordings for the "laugh track" sounds heard on sitcoms since the 1960s originated from a particularly long bit of laughter that erupted during an episode of this series.
Reportedly, the reason why this show was prerecorded for broadcast was because the network was afraid that Groucho Marx's ad-libs would run afoul of the censors. In reality, another reason was to condense the interviews to fit the allotted time with the most entertaining material Groucho was able to generate with them.