Iranian chess player Sara Khadem competes, without wearing a hijab, in FIDE World Rapid and Blitz Chess Championships in Almaty, Kazakhstan December 26, 2022, in this picture obtained by Reuters on December 27, 2022. (Photo by Lennart Ootes/FIDE/via Reuters)

South Sudanese traditional dancers prepare to welcome Pope Francis during his visit in Juba, South Sudan on February 3, 2023. (Photo by Thomas Mukoya/Reuters)

A woman athlete aims an air rifle while competing in a local shooting championship in Yemen's Huthi rebel-held capital Sanaa on January 3, 2023. (Photo by Mohammed Huwais/AFP Photo)

People pass by the floating restaurant “Silver Whale” which partially sank during ice drift on the Neva River in St. Petersburg, Russia, 27 March 2023. Rescuers try to secure it with ropes so that the restaurant is not swept away by the river. The temperatures have reached zero degrees Celsius in the second largest city of Russia. (Photo by Anatoly Maltsev/EPA/EFE/Rex Features/Shutterstock)

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 farrier attaches a horse shoe still hot from the furnace at The Household Cavalry Mounted Regiment (HCMR) at Hyde Park Barracks on March 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Ernie Lotinga, looking terrified as a gun is pointed in his face, in a scene from the play “My Wife's Family”, at the Garrick Theatre, London. (Photo by Sasha/Getty Images). 24th February 1941

Revellers gather for the start of the Annual SantaCon Bar Crawl at Father Duffy Square, a section of Times Square, on December 14, 2019, in New York City. SantCon is an event where people make donations to charitable causes and dress up as a Christmas character and visit bars around the city. (Photo by Steven Ferdman/Getty Images)