Everyone wants to get something for nothing - whether it's a lucky upgrade that means you can turn left when you get on a plane instead or heading off into the economy seats, or even getting a few extra features thrown in for free when you buy a new car.

As some of the sharpest businesses around, no-one understands this quite as well as casinos and that's why they all have a system that they call comps. It's short for "complimentary offers" and these are special treats specially designed to reward you for your loyalty to the casino in question. They're basically bonuses.

A girl peers from between light decorations at a Christmas fair which opened ahead of the holiday season in Bucharest, Romania, Friday, November 25, 2022. Municipal authorities in the Romanian capital, quoted by local media, stated that holiday season city light decoration levels will remain at last year's level and use energy saving solutions. (Photo by Vadim Ghirda/AP Photo)

Unwanted phones recreated as interactive birds, part of “Escape III” by Anthony Goh and Neil Mendoza seen on display at the Barbican's Digital Revolution exhibition on July 2, 2014 in London, England. The exhibition brings together artists, designers, film makers, musicians and architects who push the boundaries of creativity that digitial technology can offer, and runs from July 3 until September 14, 2014. (Photo by Matthew Lloyd/Getty Images for Barbican Art Gallery)

If the most popular foods of Rio de Janeiro have one thing in common, it is their informality. You can find fine restaurants in the city, but they do not set Rio apart from other places. What does set it apart, and what invariably brings its residents, known as "Cariocas," together is the unpretentious food they eat in bright, loud, crowded bars and restaurants, on busy street corners, or after a day at the beach. Here: A view of traditional bolinhos de bacalhau (fried codfish balls) in Rio de Janeiro, Brazil, May 7, 2016. (Photo by Sergio Moraes/Reuters)

In this February 1, 2017 photo, environmental activist Maruja Inquilla poses for a photo next to a Municipal waste treatment plant with water that flows into Lake Titicaca, in Juliaca, in the Puno region of Peru. “If the frogs could talk they would say, This is killing me”," said Inquilla, who recently showed up at the Puno governor's house carrying plastic bags filled with hundreds of dead frogs in protest. (Photo by Rodrigo Abd/AP Photo)

Jerome Flynn, who played Bronn on “Game of Thrones“, posed in a cage on London's Oxford Street on November 26, 2019 alongside the campaign group Farms Not Factories to raise awareness that most supermarkets and high street food chains are still sourcing their pork almost entirely from factory farms. Says Jerome "Factory Farming is one of the most horrific examples of how far we have strayed from our hearts in the relentless drive for profit and so called progress”. (Photo by Jeff Moore/Splash News and Pictures)

Hyperrealism with pencil by Karla Mialynne. Her impressing paintings are mostly created with watercolor pencils, colored markers and acrylic paint.

Some are in it just for the money, others to help buy a meal. Then there are those who trade for fun or to spend time among friends. Millions of investors – pensioners, security guards, high-school students – dominate China's stock markets, conducting about 80 percent of all trades. Retirees gather in brokerage houses dotted around China also to enjoy some company and savour the air conditioning on hot days. Some start as young as 13, trading from home with an eye on future careers in finance. Winning isn't guaranteed. This year, among the most turbulent in China's financial history, its stock markets more than doubled in the six months to May, only to crash amid concerns that growth in the country, which makes everything from cars to steel, is slowing faster than previously thought. (Photo by Aly Song/Reuters)