From childhood, our teachers and parents tell us the story of American showman and huckster Phineas T. Barnum, and his philosophy is invariably summed up with this aphorism. The trouble is, Barnum never said it, which is simply more evidence of its absolute truth.
Another often quoted line is one of truth being stranger than fiction, and the origin of "there's a sucker born every minute" is a sterling example of it.
In 1869, entrepeneur George Hull was raking in money charging admission to see the latest wonder of the century, the Cardiff Giant, at his brother-in-law's western New York farm. But after awhile, the farm became too small to support the crowds that were coming. Even worse, many recognized the Giant for the crude fake it was. Some (including the eminent paleontologist Othniel C. Marsh) had a reputation that other people would listen to. Bad for business all around. It was not surprising, then, that Hull went searching for investors who would, shall we say, "spread the risk". Hull found his investors in a group of five prominent Syracuse businessmen, who paid $30,000 for a two-thirds interest in the Giant, and then moved it to brand-new exhibit hall in Syracuse. The leader of this syndicate was banker David Hannum, who actually believed the literal truth of the statement in Genesis 6 that "there were Giants in the earth at that time". His emotional incentive to believe that the Giant was real was now matched by a financial one.
Here's where Barnum enters the stage. No money-making opportunity could escape Barnum's attention, and he had already an agent to view the Giant at the farm. The agent reported back about the crowd of 3,000 waiting to see a gypsum fake, and surely Barnum saw dollar signs. One can inagine him rubbing his hands together. And so, Barnum approached Hannum with an offer to buy the Giant for $50,000. Hannum refused that offer, and a later offer for $60,000.
At this point, Barnum did the math and realized there were better ways of making money. Such as making his own fake Cardiff Giant, and displaying it in his New York museum. And then having the chutzpah to declare that the new, improved Giant was the real one, and that Syracuse giant was a fake! Given the choice between traveling all the way to Syracuse to see a plaster fake, and seeing one in New York City, which would you choose? Soon, Barnum's crowds exceeded Hannum's. When Hannum heard that newpapers were printing Barnum's accusations, he was heard to say, "there's a sucker born every minute". Hannum sued Barnum for defamation, but it wasn't until Hull testified that the original Giant was a fake after all that Hannum discovered he was it.