Priority queues: Paying to get to the front of the line
In the US, as elsewhere, it is becoming more common to see queues where one can pay to get to the front. It brings the market to the experience of waiting in line - but some say it conflicts with the principles of fairness and equality.
Up until recently, the "serpentine" queue was the norm in America - and businesses were proud to implement them.
"There used to be a bank in New York called Chemical Bank and they used to claim that they were the first ones to have that in their bank lobbies," says Richard Larson, a queuing theorist at MIT. "Wendy's is very proud that they were the first ones in fast food to have the single serpentine line."
The model works because most members of society agree the person who's been waiting longest should be served next, he says.
But today, many Americans are waiting in a new kind of queue - the priority queue, where certain customers get higher priority because they pay.
In American airports, priority queues are now visible everywhere - at the check-in counter, at security and at boarding gates. Many airlines now board their passengers according to the amount of money they've paid for their ticket.
Like Ryanair in Europe, discount airline Spirit is both unpopular and extremely successful. People may moan that they have to pay extra to board first or get a particular seat - but the low prices mean they keep booking tickets.
Priority queues are also being brought in to other areas of American life - from highways to theme parks.
Take the Six Flags White Water amusement park in Atlanta, which implemented a priority queue system in 2011.
Some guests simply queue up for their rides. Those who purchase green-and-gold wrist bands - fitted with radio frequency technology - are able to swim in the pool or eat snacks before being alerted to their turn.
Guests who pay an even higher fee - roughly double the price of admission - get the gold flash pass, cutting their waiting time in half.
The company says it has been a huge hit and is now installing the system in all of its American water parks.
I loved using the flash pass, but when I saw a group of teenage girls glaring at another group of teenage girls all wearing gold wrist bands - I wondered if priority queues were adding to the polarisation in American society, already a hot political issue. Is it really a good idea to further divide citizens into first and second-class citizens?
The priority queuing system has also started to be extended to the public sphere. Many people who drive to Six Flags White Water take Interstate highway I-85.
In October 2011, Atlanta created a priority lane on the highway for drivers with a Peach Pass - the price of driving in the lane changes depending on how much traffic there is.
Critics call them "Lexus lanes", because they claim the lanes benefit only the rich who can afford expensive cars.
Aside from the cost of the express lanes, some drivers are also upset that they replace car pool lanes - special lanes for cars with two or more passengers.
Overnight all the car pool drivers who used to ride free were pushed into the general lanes, making traffic worse for everyone except those who pay.
"I used to be able to drop my daughters off at the bus stop, hop in the car and start my commute. I'd usually arrive at work 35-40 minutes later," says Chris Haley, who blogs at Stop Peach Pass.
"But the very first day this was implemented my commute was an hour and half. It was like that the next day and the next day… it went on for weeks."
He says he cannot afford to spend $120 (£74) extra a month to commute - and he's now had to stop dropping his daughters off.
The Georgia Department of Transportation defends the express lanes - it says they offer a choice to frustrated Atlanta drivers.
Certainly some commuters appreciate them. "I like being able to go around all these crazy people in traffic," says graphic designer Clint Keener.
"To get to work on time, fresh, not stressed out. To me, my time is worth money, my time is worth a dollar. It's as simple as that."
But Georgia state senator Curt Thompson calls them "un-American".
"This is not about improving traffic times. It's just about giving options to people who can afford it.
"What it does is it creates what I call the politics of envy. It separates the haves and the have-nots," he says.
"We've always prided ourselves on not being so stratified. Our founding fathers never had this idea of, 'I got mine, now you go get yours'. That's not anywhere in the constitution, the bill of rights, the declaration of independence. But that's what this creates."
If the use of priority lanes has raised the ire of some of Atlanta's residents, bringing the priority queuing mentality into the American college system has proved even more controversial.
California's community colleges have provided generations of low-income students access to higher education. However, budget cuts have forced some colleges to reduce the number of classes they offer - and getting a seat can be tricky.
At Santa Monica College in California I saw students sitting on the floor and standing in the hall hoping to get a coveted seat in one of the over-subscribed classes.
"Our classes are basically completely filled, they're 100% full. And it's maddening for us because we pride ourselves on access," says college president Chui Tsang.
Desperate to widen access, last spring he came up with a programme he called Advance Your Dreams.
Tsang's plan would enable students to pay up to 400% more for a guaranteed seat in a class, and the money generated would have allowed extra classes to be arranged.
"It's like a Robin Hood system," he says. "Those who can afford it can pay a little higher and the excess revenues can help subsidise those who cannot afford the same price."
But not all students were convinced. Student president Harrison Wills says the proposal discriminates against poorer students.
"What you're going to have is a competing group of people applying for the cheapest classes and then those that don't get it, those who can afford it will go to the second tier," he says.
Those who could not afford it would have to wait and try to get on the course again at a later date.
Disquiet over the Advance Your Dreams programme led to a protest at a meeting of the school's trustees, which span out of control, leading campus police to pepper-spray a number of students.
The California chancellor of education then requested that the college put the controversial programme on hold. Tsang has not given up though, and hopes to reintroduce it at a later date. He says he is still baffled by the outcry.
"Freedom of choice is a fundamental right that we have in the United States," he says.
"And in this system when you tell someone that, 'Yeah, you have money but I cannot allow you to make a free choice because it's not fair,' that's insane."
Americans have a deep-rooted belief in the market and since priority queues can generate revenue it's no surprise that they are turning up in the public sector as well.
But are traditional American values like fairness and equal opportunity really compatible with letting someone buy their way to the front of the line? And what happens when the people who pay more want more?