Thanks to a technical error, some consumers on Thursday were able to land round-trip tickets on Delta Air Lines for under $50, which the carrier said it will honor.
"For a portion of the morning today, some prices on delta.com and other booking channels were incorrectly displayed, resulting in lower-than-usual fares for customers," a Delta spokesperson said.
"The situation has been resolved and the correct prices are being displayed. Delta will honor any fares purchased at the incorrect price."
Department of Transportation regulation says if a consumer purchases a fare and receives confirmation of their purchase, then the seller cannot increase the price, even when the fare is a "mistake."
George Hobica of Airfarewatchdog.com — an airfare alert and advice site — said Delta could have decided not to honor the mistaken prices and just paid a fine from the DOT, but he said consumer backlash would be harsh and hard to recover from.
"Should they have to pay for the mistakes of their employees? I don't know, but it would cause some uproar if they didn't," Hobica said. "They could face a hefty fine if they don't honor the prices ... the fine may have been cheaper than the cost of the mistaken flights."
Kristen Lich, a college professor and mother of three, was able to snag five round-trip tickets (for two adults and three children) from Chicago to Idaho for a total of $242 — the cost of the trip is normally nearly 10 times that price.
"My brother lives in Idaho, so every couple of weeks I look to see how much the tickets cost, and it's usually $500 or more," Lich said. "My husband and I would never be able to buy these tickets for all five of us at regular price."
Lich said she also spotted flights from Raleigh, N.C., to Maui, Hawaii, for just $180, but by the time she was ready to purchase the tickets the glitch had been fixed and the flight was listed at around $1,800.
"I guess we moved too slow, but I just wanted to see what else we could book for cheap," Lich said.
Airlines have posted so-called mistake fares before. Airlines generally decide on a case-by-case basis whether they'll honor the ticket.
Delta did not say how many tickets were sold accidentally, or how much it will cost them.
This is not the first time a Web glitch has resulted in consumers receiving "mistake fares." A United Airlines glitch in September allowed some customers to book flights for free.
Follow CNBC's Karma Allen on Twitter @iam_karma.
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