There are a thousand photos of Groucho Marx on the Internet. For some reason, when someone's designing a book or CD or DVD cover and they need one, they go to the web and a surprising percentage of the time, they select one that is not of Groucho Marx.
See that cover above for the Penguin Books release of The Essential Groucho? Well, that's not a photo of Groucho. That's Alfred Eisenstaedt, a well-known German photographer. Once for a photo shoot, he got dressed up as Groucho and took that picture and it often pops up on articles and merchandise as if it's the real guy. As I mentioned here a few days ago, my pal Steve Stoliar is working with director Rob Zombie on a movie about Groucho. There are several articles about it on the 'net and I found at least three that used the photo of Eisenstaedt, thinking it was Marx.
And see that cover above for a DVD of old TV show comedy? Not Groucho, either. That's one of my other pals, Frank Ferrante. In fact, it wouldn't surprise me if the person who used that picture for the DVD cribbed it from this site. If you do a Google image search for shots of Groucho, you'll see a lot of Ferrante since Google doesn't really identify faces. They just link an image to the nearby text.
I have nothing to add to this except that I thought it was worth mentioning. Odd to find out that "The One…the Only…Groucho" is other people.