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Both Southwest Airlines and Delta Airlines released flash mob videos this week.

The next time you go to the airport, wander the terminal and get on a plane, be forewarned that you are walking into flash mob territory. This week, Southwest and Delta Airlines became the latest carriers to join the marketing craze of posting flash mob videos on YouTube.

A flash mob, by definition, is a large group of people who assemble suddenly in a public place to perform an unusual and seemly pointless act for a brief time, then disperse, often for the purposes of entertainment, satire and artistic expression.

It's also increasingly one of the cheapest ways for a company to get brand recognition out to the masses by making a video that's sure to go viral.

What are the key ingredients? Amateur dancers, company uniforms, a dance song and a video camera.

Corporate flash mobs are no spontaneous eruption, but a carefully planned marketing scheme.

Southwest Airlines began service at Atlanta's Hartsfield-Jackson International Airport on Saturday, to the tune of a flash mob with the workers breaking it down in Terminal C. The routine was complete with disco lights and Jermaine Dupri's Welcome to Atlanta.

The Southwest employees stripped from their uniforms into bright yellow Atlanta at Last T-shirts as they moved from song to song with nervous excitement.

Last week, Delta employees took the flash mob to the next level, flash mobbing across the country. Their viral video starts out with some questionable singing and progresses into a flash mob extravaganza as employees take over airports from Atlanta to Detroit.

We hope the video shows customers what the culture at Delta is all about and that we truly love to have fun, Delta spokewoman Ashley Black told ABCNews.com when the video went viral.

With weekly TSA complaints and endless commentary about the hassles of travel in a post-9/11 world, these videos are an attempt to show us -- the everyday traveler -- that it's not all security checkpoints, pat downs and Words With Friends denials - sometimes its dancing pilots and kick lines.

A Finnair Bollywood-style flash mob organized in January to mark India's 63rd Republic Day garnered well over 4.5 million hits on YouTube. All it took was about 20 blonde flight attendants dressed up in traditional Indian garb and some bouncy Bollywood moves to make the video a viral hit.

In December, there were even more videos of airline employees doing zany things. Who could forget the Cebu Pacific flight attendants doing their safety dance to All I Want For Christmas Is You, or the American Airlines runway workers line dancing at Chicago's O'Hare?

Part of the reason these videos go viral is our collective joy in watching large groups of people make a fool out of themselves on a grand scale. It's the same reason we watch reality television. These airline workers are not professional dancers, choreography is done in house, and the employees never quite seem to have had enough time to perfect the moves.

It's silly and it's fun. It's marketing without us ever realizing that's what it is.

View the latest flash mob videos below: