Nana Takano and Kaito Toyoshima, winners of the Shanghai preliminary and Asian Championship, compete in the final of the World Tango Championship final in Buenos Aires, Argentina, 27 August 2024. (Photo by Juan Ignacio Roncoroni/EPA)

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.

Giant Olympic rings are towed on The River Thames past The Tower of London on February 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)

People run along a street as rain caused by tropical storm Alberto, the first named storm of 2024 Atlantic hurricane season, falls, in Monterrey, Mexico. on June 19, 2024. (Photo by Daniel Becerril/Reuters)

Japan's Naomi Osaka returns the ball during her match against Slovakia's Dominika Cibulkova during the Madrid Open tennis tournament, Sunday, May 5, 2019, in Madrid, Spain. (Photo by Andrea Comas/AP Photo)

A team from Woody's Ice Cream shop wrangle a large inflatable dinosaur down the street during the Independence Day Parade in Fairfax, Virginia July 4, 2015. Americans marched in star-spangled parades, ran relay races, gathered for fireworks shows and crowned a new world hot dog eating champion as they celebrated Independence Day in traditional style on Saturday. (Photo by Jonathan Ernst/Reuters)

Paragliders fly towards the landing area of the “Acro Show” above Lake Geneva in Villeneuve, Switzerland on Sunday, August 26, 2018. (Photo by Valentin Flauraud/Keystone via AP Photo)

Italy is the latest country to boast a sеx doll brothel amid predictions the market for robot romps is “going to explode” world-wide. “LumiDolls”, which operates robot knocking shops in Barcelona and in Moscow is now opening a bot bonking branch in the Italian city of Turin on September 3, 2018. (Photo by Giulio Lapone/IPA/Rex Features/Shutterstock)