Last Tuesday evening, the travel Twitterverse was abuzz with news of what one industry pundit called the “sale of the decade”: a slew of late summer and fall fares on Delta Air Lines from the USA to Europe for less than $250 round-trip, taxes included.

By late the next morning, Delta’s pricing glitch (the airline had apparently neglected to add a $200 fuel surcharge) was fixed, and the eye-popping fares were history. But for nimble bargain hunters, the social-media phenomenon known as Twitter had proven its worth as a way to snag a terrific travel deal.

Once dismissed as a fad for high-tech narcissists, the 140-character, real-time updates, or tweets, are increasingly popular among hotels, airlines and other travel companies as a way to interact with customers - and pitch offers. While many deals are available elsewhere, others are unique to Twitter.

Because fares and inventory change so rapidly, ”being first to know about an airfare sale is very important. It may take people a few days to open e-mail, but Twitter is a great way to reach people in cellphone fashion,” says FareCompare.com’s CEO, Rick Seaney, who adds that his alerts highlighting the Europe sale resulted in about 450 bookings. FareCompare.com, which has about 3,100 “followers” at twitter.com/rickseaney, recently launched Twitter feeds from more than 100 U.S. airports that offer a combination of location-specific deals and general advice.

”The medium is still a blank slate, and people are throwing everything on the wall, trying to see what works,” says Adam Rugel of buzz.trazzler.com, a just-launched site that posts bargains found on Twitter.

Some recent examples:

— Since late May, United Airlines has offered the company’s approximately 12,500 Twitter followers five steeply discounted “Twares,” including last week’s $53 one-way fare between Denver and Phoenix.

— Pleasant Holidays’ new Twitter and Facebook offers include weekly last-minute specials to Hawaii, such as $200 round-trip fare to Honolulu from Los Angeles or San Francisco including a three-day car rental, and expand to Mexico and the Caribbean next month.

— Through Aug. 28, San Francisco-based Joie de Vivre’s weekly Twitter Tuesday and Facebook Friday deals offer hotel rooms as low as $50 per night. The discounts are posted for only one hour and must be booked at summercalifornia.com.