HOUSTON — Scrunched in the packed coach cabin, J.P. Maxwell eyed the lone empty seat in first class. An elite flier on Continental Airlines, he was upset. Maxwell was convinced he should have been automatically upgraded on the recent four-hour trip.

During the flight, the Internet entrepreneur hacked out a 526-word missive that he later posted in a popular online chat room, www.flyertalk.com. "I consistently pay several hundred more to fly (Continental) and this is what I get?" Maxwell vented on the site.

Lurking in the chat room was Scott O'Leary, a customer service guru at Continental who spends several hours each day prowling such Web sites for customer complaints. O'Leary quickly discovered that Maxwell had never been told that he had been upgraded and had been left to languish in coach. With the passion of someone who had discovered a major flaw in the airline's operations, O'Leary alerted company executives to prevent similar foul-ups, ensured that Maxwell got a free upgrade and posted an explanation for the mistake in the chat room.

The recent exchange highlights the growing importance that airlines are putting on monitoring travel chat rooms, often the only forums where far-flung travelers can trade horror stories and swap tips. Flyertalk alone has more than 130,000 members, and thousands of others visit the site each day to read the postings.

Representatives of Continental's competitors say they also monitor the blogs and chat rooms to quickly pick up on problems. US Airways, for example, is eliminating a $25 fee it used to charge its top fliers to switch their flights at the last minute, in response to complaints posted in chat rooms.

American Airlines' customer service managers and spokesmen visit the sites because those "give you a quick pulse check on the industry," said Roger Frizzell, vice president of corporate communications, adding that the company is careful in how it responds to online commentary because the anonymous nature of the sites can sometimes lead to "wild accusations without any fact or merit."

United Airlines' customer-service specialists have similar concerns about the anonymous nature of the airline blogosphere. To get a better gauge of what its customers think, the airline created its own version of the chat rooms in April and invited 200 of its highest-mileage fliers to join the private discussions, the carrier said. United representatives said they pose online questions to the customers and monitor their complaints. "We view it as a very rich way to get data," said Barbara Higgins, vice president of customer experience.

Still, no carrier has weighed into the often passionate, quirky and nitpicky airline blogosphere like Continental. The airline has a long history with customers who populate the blogs and chat rooms, particularly those who frequent the Continental forum on Flyertalk.

The airline has sponsored two events in recent years for Flyertalkers at its Houston headquarters, drawing more than 200 people who paid their own way to each get-together. At the meetings and in private e-mails, some Flyertalkers pestered Continental chief Lawrence Kellner to get his company more involved in the chat room.

Kellner agreed, but only after finding the perfect candidate to join the forum, where customers spend hours chatting about upgrade policies, the best airport lounges and strategies for earning extra frequent-flier miles. O'Leary, 35, is a Continental marketing director and admitted airline geek whose sole career goal growing up was to work for a major carrier.

Flyertalkers generally agreed that they enjoy having O'Leary in their forum because he doesn't overwhelm them with company propaganda and usually answers their questions. And the airline fanatic "has been through as many airports and delays as the rest of us," said forum member Richard Baum.