(NewsNation) — An estimated 45 million people will bet on this year’s March Madness tournament, with sports betting becoming legal in more states and apps allowing those not near a betting window to place their wagers online.

NewsNation’s Alex Caprariello spoke to people in Las Vegas looking forward both to seeing their teams play in the Big Dance and making some serious cash at the betting window. Ivetta Abramyan, from Washington, D.C., said, “I have goosebumps just talking about it!”

Preston Lopes, from Albuquerque, was a little more focused, “It’s March Madness. It’s the best time in the world to bet right now. I’m here to win some money. Gotta dial in. Gotta get focus.”

Everyone’s got their own method, but choose carefully. One slip can lead to a busted bracket. Concentration is key for Lopez. He and his friends flew in from Albuquerque to sit front row at the Westgate Sportsbook.

A man known as “Michigan Mike” Frontera always bets on the underdogs, and he knows a few things about good bets and bad beats. He says, “Don’t bet with your heart. I’ve done that with the Lions, and it’s cost me a lot of money.”

Vegas is giving Gonzaga the best odds to win it all, and according to the American Gaming Association about 17% of bettors like that pick. The next favorites to win are Duke and Kentucky. Duke’s a “heart” pick for a lot of people since it will be legendary coach Mike Kryzyzewski’s last ride.

However it all shakes out, it’s estimated that $3.1 billion will have been wagered on the games by the time all is said and done.