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Dance Marathons via Wikipedia:

Marathon dancing fit in nicely with the 1920s craze for breaking records and stretching human endurance, with records being set in flagpole sitting, mountaineering, aviation, and more. Dance marathons started similarly, and ended up being one of the most widely attended and controversial forms of live theater.

Contestants and spectators alike bought into the staged excitement and competition. Spectators could cheer, make wagers and root for their favorite team, even interacting with the dancers, chatting with them and throwing money. Contestants were enticed by the potential for fame and fortune, from prizes of several thousand dollars to performing contracts, and were fueled by the audiences’ support and applause. Like professional wrestling, the contests were fixed, but both sides bought into the simulated reality of it and participated heartily, provoking each other and egging each other on. The newest episodic entertainment, spectators would return day after day to follow their heroes and see more drama unfold.

Many contestants, considering themselves theater professionals based on their marathon experience, traveled the country competing in one marathon after another. Especially during the Depression, marathons offered work, shelter, food, and potential for extra money and more. Contestants hoped to have careers in films, and though many took roles as extras, only the few who were veteran performers before entering, like June Havoc and Red Skelton, found real fame and entertainment careers after their marathon days.