If you fly, chances are you have a story to tell about an uncomfortable airline seat.

Vicki Morwitz does. Hers involves a long-haul plane trip, a minuscule economy-class seat, and a circuitous routing that deposited her at her destination feeling exhausted and irritated.

So when a friend invited her to test a new online booking site that evaluates airline seats for their comfort, she had to try it. "I care about fares," says Morwitz, a business professor who lives in New York. "But I also care a lot about the travel experience."

That site, Routehappy (www.routehappy.com), launched last month with a lofty promise of showing you the best possible flight based on price, seat comfort, and schedule. If it succeeds, it could change the way people fly.

"Consumers care about experience, even if they don't acknowledge it," says Robert Albert, Routehappy's founder and chief executive. "In spite of being so publicly blase about taking commercial flights, passengers pay attention to the experience."

Albert cites a recent survey by the travel consultancy Hudson Crossing, which suggests that a majority of passengers make purchasing decisions based in part on amenities and customer service. Even the type of aircraft can sway them.

But passengers aren't the only ones who have been blase. For years, airlines enthusiastically embraced the idea that in economy class, a seat is a seat. Indeed, within the last generation, most seats in the back of the plane shrank to a standard 171/2-inch width with 31 inches of "pitch," or space between seats. For the typical American adult, that effectively turned a transcontinental flight into an ordeal and made long-haul international flights almost unbearable.

It wasn't until the airline industry stumbled upon the idea that it could charge more for certain economy-class seats that it slowly began to turn away from a concept that has been called "commoditization." When airlines could extract more money for, say, an exit-row seat, which must have more legroom under Federal Aviation Administration regulations, or to reserve an aisle seat, the idea that all airline seats are created equal started to unravel.

The transition isn't complete, according to Hudson Crossing analyst Henry Harteveldt. It's plainly obvious that some seats are better than others, but he says airlines need to "wake up" to that reality.

Morwitz already knew that when she signed in to Routehappy to book a recent flight from New York to Istanbul. But the nonstop flight offered by her preferred carrier had been discontinued, and in order to stay with the airline and collect miles, she would have to connect through Amsterdam or Paris, which she didn't want to do. Both connections required long stopovers, and the fares were expensive.

Routehappy suggested an alternate route with more comfortable seats, via Moscow on Aeroflot. It also ranked the flight based on seat comfort, in-flight entertainment systems, available wireless Internet connection, and aircraft type, assigning the route a score from 1 to 10.

"I remember all the old horror stories about Aeroflot, so it was a very happy surprise when I read some very nice reviews about the airline," Morwitz says. "I decided to give it a try and had a very pleasant flight experience - one I definitely would not have taken if not for Routehappy."

Routehappy may debunk a few persistent and unhelpful myths about air travel. The first is an oft-repeated mantra among airlines that air travelers care only about price when considering ticket purchases. It's a "truth" that has made air travel a miserable experience for most economy-class passengers, as air carriers used it to justify moving seats closer together and adding new surcharges to their ticket prices.

"While I agree that everyone cares about price, oftentimes consumers are comparing 10 or more options at the same price," says Albert. "Why wouldn't you choose an extra inch or two of legroom, streaming television, or WiFi over a cramped seat with no amenities?"

A related myth: Generally speaking, passengers wouldn't pay more for a comfortable seat. During Routehappy's usability testing, the company noticed that certain amenities - most notably, a roomier seat - enticed air travelers to pay extra for their tickets.

That doesn't surprise Harteveldt, the airline analyst. "If all people cared about was price," he says, "then Spirit would be the largest airline in the world."

But a company such as Routehappy could threaten the status quo of modern flying. The detailed information on seat comfort and amenities, previously hidden from the traveling public, could undermine the highly profitable loyalty programs, driving customers to book the best ticket for them, rather than one that helps them accumulate the most frequent-flier miles.

"I think Routehappy can help change the airline industry," says Morwitz, an expert on consumer behavior and marketing, and a happy Aeroflot customer. "Ultimately, this can be better for the airlines themselves, as they can differentiate themselves, instead of being viewed as interchangeable commodities."