The staggering size of the Mega Millions jackpot also makes this lottery special, attracting people who want to participate in a social, news-making event, says Jane Risen, an associate professor of behavioral science at the University of Chicago's Booth School of Business.
"The lottery happens every day," she says, "but for some people it has to reach almost a cultural threshold before it becomes the thing to think about."
What develops, she says, is a feeling of "anticipated regret." In short, people worry about not playing.
"It's some version of "What's the harm? I wouldn't want to be the idiot who didn't play the Mega Millions. What if I was the winner?'" Risen says. "It's a better safe-than-sorry philosophy: 'I'd better buy a lottery ticket just in case I was going to the winner.'"
Kathy Malzewski, a 67-year-old retiree from Milwaukee, never buys Mega Million tickets. But while she was in a grocery store Monday, buying scratch-off tickets as stocking stuffers, she decided on a whim to buy a single ticket because of the enormous jackpot.
What would she do if she won?
"I'd go into a nice retirement community myself, but I'd be generous," she said softly. "I'd help Habitat for Humanity, help the homeless, give a lot to charity."
Malzewski also said she'd travel around the United States. She saw the ocean for the first time in May and recently visited the Grand Canyon. She'd like to go to New York or Florida's Everglades as well.
"Why not?" she said with a smile. "There are so many places to see."
She'll know Tuesday night if she has an instant way to finance those dreams.
"I'm not lucky. I never win anything," she says. "But I might today. A person always has a little hope."
Associated Press writers Lucas Johnson in Nashville, Tenn., and Dinesh Ramde in Milwaukee contributed to this report.