Angry tweets, viral videos are teaching airlines to observe social media, and respond.

For air carriers in particular, "the world changed" last April after the Chicago dragging incident, Oscar Munoz , chief executive of United Continental Holdings Inc., said in a June talk at the Wings Club in Manhattan. This new reality is largely the reason so many airlines now staff social media departments around the clock, offering quick service to customers while monitoring Internet chatter for potential trouble, celebrity tweets and video snippets that could go viral.

A survey released Tuesday by customer service firm Conversocial attempts to quantify how large airlines are interacting with the public on Twitter and Facebook. The firm sought to measure how often and how rapidly 20 big carriers respond to Internet posts directed at them-many of which originate from unhappy customers who want the airline to remedy a problem.

Among North American carriers, JetBlue Airways and Virgin America, part of Alaska Air Group, were quickest to respond to Twitter posts-in less than five minutes-while United was the laggard at more than 90 minutes, according to Conversocial, which develops social media management tools.

Of all the Twitter posts directed at North American airlines, American Airlines Group Inc. responded to the largest share, at 32.5 percent. Air Canada reacted to the least amount at 10.3 percent. The vast majority of airline responses relate to customer service issues, although some react to more general complaints and compliments, Conversocial CEO Joshua March said.

The data were compiled from Twitter posts made between Oct. 5 and Oct. 8 aimed at airlines based in North America, Europe and the Middle East.

"We recognise that oftentimes social media is the most convenient way for customers to interact with us and we are continuing to work hard on a daily basis to improve our response time," United spokeswoman Maggie Schmerin said in an email. The airline wouldn't reveal how many people work on its social media team but she said United plans to increase that staff by "more than 150 percent" in the first quarter.

The slowest Twitter responder in the European-Middle Eastern grouping, Finnair, didn't respond Monday to a request for comment. Deutsche Lufthansa, the quickest European airline to respond, was also tagged as the least responsive carrier in that group, meaning the German company reacted to the fewest number of Twitter posts but was speedy when it decided to do so.

Airlines initially began using social media as a public relations and branding tool, not as a customer service channel, March said, but passengers soon bent the platform to their own purposes. "Customers started using it to escalate stuff they are really upset about," he said.

The survey has no data to correlate a relationship between how quickly an airline responds to a customer tweet and how well that company may resolve problems. However, there has been a strong link between how smaller airlines (and airports) perform on these surveys and ultimate customer satisfaction. The latest J.D. Power airline satisfaction study, released in May, ranked Southwest Airlines and JetBlue atop the North American airline heap. The annual Airline Quality Rating study from Embry-Riddle Aeronautical University and Wichita State placed Alaska as the top U.S. performer.

The last major network airline to score first in the latter poll was US Airways, in 2002.

Despite the public's fascination with customer-service meltdowns, Twitter Inc., Facebook Inc. and other public Internet platforms may soon become old hat for customers seeking help-the growth in customers messaging directly, and privately, with airlines is exploding, March said.-The Washington Post.