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.

People take part in a Halloween street party at Lan Kwai Fong on October 31, 2016 in Hong Kong. Halloween, a contraction of All Hallows' Evening, falls on the day before All Saints' Day on November 1, a holiday when Christians remember their deceased loved ones. (Photo by Lam Yik Fei/Getty Images)

Crowds look on as the super moon rises behind the Fremantle War Memorial at Monument Hill on November 14, 2016 in Fremantle, Australia. A super moon occurs when a full moon passes closes to earth than usual, with the November 14th moon expected to be closer than it has been in over 70 years. (Photo by Paul Kane/Getty Images)

Yanna Xian, 24, and her boyfriend Mitch Brown, 27, were swimming while on a boat tour off Honolulu, Hawaii last year, when a curious two-week-old humpback approached them. (Photo by South West News Service)

An empty beer bottle stands in front of the buildings of the banking district in Frankfurt, Germany, Friday, May 21, 2021. All people gathering on the square for drinks and food left when the police started checking if they are abiding by the coronavirus restrictions. (Photo by Michael Probst/AP Photo)

A Mexican tourist ended up with broken ribs after attempting to make the most of a photo opportunity with some deer in October 2023. Gian Carlo Triacca, 42, was on holiday in Greece when he was attacked from behind. His wife, Erika, 40, managed to record the moment the deer charged. (Photo by Gian Carlo Triacca/Caters News Agency)

A demonstrator gestures during protests around the Argentine Parliament in Buenos Aires, Argentina, 10 March 2022. Serious disturbances were registered in the surroundings of the seat of the Argentine Parliament when demonstrators protesting against the new agreement with the International Monetary Fund (IMF) clashed with the police of the city of Buenos Aires. (Photo by Juan Ignacio Roncoroni/EPA/EFE)

Behishta,11, listens during 4th grade class at the Zarghoona high school on July 25 2021 in Kabul, Afghanistan. The Zarghoona girls high school is the largest in Kabul with 8,500 female students attending classes. The school opened after a nearly two-month break due to the coronavirus (COVID-19) pandemic. (Photo by Paula Bronstein/Getty Images)