It costs the airline the same amount of money to get each person from point A to point B, but clearly some passengers are more profitable than others. (That's why airlines offer leisure travelers a $200 or $300 voucher to voluntarily be bumped to a later flight -- they often want to fill the seat with a high-yield customer paying three times that.)
The major airlines refused to give out details of these secret rewards programs, fearing that the competition will try to use such information to steal customers. But FlyerTalk.com's Petersen, who was once a Global Services member himself, said members of these clubs often spend $50,000 to $100,000 a year with the airline.
The airlines can also offer membership to influential people such as the heads of large corporate travel departments, celebrities or politicians.
Petersen said it's like Studio 54, "They pick you, you don't pick them."
'Up in the Air" director Jason Reitman, for example, was given his own membership card by American.
"Somebody could fly once a year or 100 times a year," said Billy Sanez, director of advertising and promotion for American Airlines, who worked with the 'Up in the Air' crew. "There's no preset determination for it. It's invitation only. It is our very best customers."
Membership doesn't necessarily guarantee membership for life. Each year, American sends out letters either renewing memberships or not.
"I wouldn't call it a secret society, but it's an exclusive group," Sanez said.
In the movie, Clooney's character shows his American Airlines Concierge Key card to a woman he is hitting on at a bar. Her response: I had heard rumors, but I didn't know these really existed.
"This is pretty sexy," she says, picking up the card.
While the Concierge Key program does exist, the movie takes a bit of artistic license with other parts of the services. Clooney's character is seeking to get 10 million frequent flier miles.
"I'd be the seventh person to do it. More people have walked on the moon," he said.
The major airlines refused to divulge how many people have reached that target, but airline officials who were willing to talk -- including from American -- said the number is more than 12, the number who have walked on the moon.
"That line is not accurate," Sanez said.
And while there is some recognition when a passenger hits the 10 million mark, American does not put the traveler's name on the side of a plane or have the person meet the "chief pilot," as the movie claims.
Phillip Dunkelberger is one of those passengers. He currently has more than 11 million miles with American and is a member of Concierge Key. (There are several American AAdvantage members who have more miles.)
He is president and CEO of PGP Corp., a global data security firm. Each year, he is on the road for at least 30 weeks.
Dunkelberger hit 10 million miles about two years ago when flying out of New York's John F. Kennedy International Airport. At the gate there was an announcement about his milestone and then Dunkelberger was escorted in a mini-ceremony down the ramp to the plane.
Dunkelberger said Concierge Key provides him with unparalleled service and makes him feel looked after.