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.

Girls enjoy nice weather at a park in front of the Pothonggang Department Store in central Pyongyang October 11, 2015. (Photo by Damir Sagolj/Reuters)

Pedestrians are falling after a gust of wind in Munich southern Germany, Tuesday, March 31, 2015. One of the strongest storm fronts in years hit Germany on Tuesday, as Storm “Niklas” uncovered roofs, toppled scaffolding and caused severe disruption to rail services. (Photo by Sven Hoppe/AP Photo/DPA)

People hold umbrellas as they walk past a flooded street in Taiyuan, Shanxi Province, China, July 19, 2016. (Photo by Reuters/China Daily)

A retired man (L) looks toward two girls wearing miniskirts, July 13, 1969 in Nice, France. (Photo by AFP Photo)

Galagos, more commonly known as bush babies, are tiny African primates with remarkable jumping abilities. Thanks to the elastic energy stored in the tendons of their lower legs, small-eared galagos can jump 6 feet straight up in the air. (Photo by Traer Scott/Chronicle Books)

English model Leomie Anderson attends a private view of “The Mandalorian And The Child”, a special portrait being unveiled in collaboration with the National Portrait Gallery, on October 29, 2020 in London, England. The portrait will be available to the public to view for free on the 30th and 31st of October, and marks the arrival of the highly anticipated second season of “The Mandalorian” on Disney+. (Photo by David M. Benett/Dave Benett/Getty Images for Disney+)

A runner dressed as Spiderman poses before the annual “Sao Silvestre Run”, an international race through the streets of Sao Paulo, Brazil on December 31, 2021. (Photo by Carla Carniel/Reuters)