Free Flights to Vegas, New York and Cancun?

Nov. 30, 2010— -- Matthew Klint might have just landed one of the best travel deals ever.

Next month, Klint, his brother and his uncle are all flying to Las Vegas and staying in two rooms at a five-star hotel. The total cost: $44. Throw in a $200 food and drink credit and they are actually making $156 off the trip.

How did Klint score such a deal? The 24-year-old Philadelphia law student saw a promotion -- possibly an error -- on Expedia's Canadian website and snagged it quickly.

Then he started booking other trips for friends and family. Ultimately, Klint purchased 15 tickets, most of them for free.

"I always recommend to people: book now and ask questions later," said Klint, who also has a blog about flying called Live and Let's Fly.

A few hours after Klint booked the tickets, Expedia caught the error and changed its promotion requiring all trips to start in Canada.

Stay Up to Date on the Latest Travel Trends from ABC News on Twitter

Savvy travelers had caught on to a promotion where Expedia was offering $300 off any air and hotel package to Cancun, New York or Las Vegas. The deal was originally supposed to be just for Canadian travelers and aimed at longer vacations. But deal watchers saw it and word spread quickly on the Internet.

Besides his one-night Vegas trip, Klint is taking two mileage runs from his parents' house in Los Angeles to New York, just to get the frequent flier miles needed to re-qualify for elite status next year. The cost: completely free.

"This deal was so lucrative. There was no minimum stay," he said. "It just seems that Expedia dropped the ball and should have put a minimum night requirement."

Expedia declined several requests for an interview and only would say that it is honoring all bookings.