The United Airlines boycott is not backing down - here's how it could affect sales

United Airlines is in the middle of a PR nightmare.

In case you missed it, on April 10, a video showing police officers dragging an Asian male passenger off a flight went viral. The airline reportedly needed room on the overbooked plane to move crew for another flight. When it couldn't find enough volunteers, United selected the 69-year-old man, Dr. David Dao, and several other passengers to deplane.

Dao refused, and aviation officers dragged him down the aisle and off the flight. He later went to the hospital for non-life-threatening injuries to his face.

Some people are now threatening to boycott the airline, using the hashtag #BoycottUnited (which has over 3.5 million impressions on Twitter).

The research firm YouGov has also been tracking consumer perceptions of United every day since July 2016. It asked consumers to give the airline a likeability score from -100 to 100, with zero being neutral. In a survey of 4,800 different people daily from April 9 to 16, United score plunged from 1.8 to -64.

Despite the backlash, the incident and boycott will likely not greatly impact United's sales, Erich Joachimsthaler, CEO of the consultancy firm Vivaldi, tells Business Insider.

He notes that the airline has a monopoly over certain routes, so many travelers will have no choice but to fly United. Those who buy flights through third-party discount sites, like Kayak or Expedia, will also likely want to get the cheapest tickets possible, even if it's through an airline they dislike.

"If you live in Charlottesville, Virginia, you simply have no other way to go to LaGuardia [in New York City] unless you fly United," Joachimsthaler says.

The monopoly over flight routes is part of a calculated strategy by United, and is largely a product of its 2010 merger with Continental Airlines, he adds. Due to the consolidation, United is able to reduce competition while increasing fares. This isn't unique to United either - a dozen major airlines have merged in the past 12 years, and today, 80% of America's air traffic is divided among four mega-carriers: American, United Airlines, Delta Air Lines and Southwest Airlines.

Joachimsthaler says people are reacting strongly to the video, because most travelers can identify with Dao even if they've never been personally dragged off a flight. The video taps into consumers' growing dissatisfaction with airlines' declining service standards, like charging additional bag fees or overbooking flights.

"This is not about overbooking. I think the incident is about airline bullying," he says. "We have all experienced airline bullying in one form or another. In this case, the airline bullying not only went way out of control, it also happened with an airline that has a history of real customer service problems. It's an issue that has come to the forefront of American travelers' minds."

Though the United incident may not hurt the airline's sales, Joachimsthaler predicts that it will still have ripple effects that could make the airline less efficient on a daily basis.

"The NPS ratings will continue to go down and spiral, and now consumers will be extremely sensitized for anything that will occur on flights," he says.

United CEO Oscar Munoz responded to the incident by calling Dao "disruptive" and "belligerent," but apologized a day later. Joachimsthaler says this was the wrong response because it treats the incident as a PR crisis rather than a systemic issue within United.

"It reinforces United's posture of having a do-nothing attitude and that they are just providing lip service to the press," he says. "And even though they are being punished thanks to social media and iPhones, they are not suffering the harm, because it will not affect sales - not even in the short term."