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.

The Royal Castle is seen a veil of heavy winter smog in Budapest, Hungary on January 30, 2017. (Photo by Laszlo Balogh/Reuters)

A girl reacts while getting a nasal swab sample at a testing and screening facility for the new coronavirus in a hospital in Karachi, Pakistan, Friday, July 17, 2020. (Photo by Fareed Khan/AP Photo)

People walk under Australia's iconic landmark Harbour Bridge in Sydney on April 3, 2019, as heavy fog blankets the city. Low visibility due to heavy fog affected traffic in the city and caused flight delays at the Sydney airport. (Photo by Saeed Khan/AFP Photo)

The silhouette of a woman is reflected in a puddle as she crosses a square in front of the Peter and Paul Cathedral in Saint Petersburg on March, 17, 2019. (Photo by Olga Maltseva/AFP Photo)

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

Revellers brave the chill and jump into the water at Carnlough, Co. Antrim, Northern Ireland on January 1, 2024. (Photo by Arthur Allison/Pacemaker)

A pedestrian carries a shopping bag and looks at his phone while walking past a mural decorating a construction site in central Sydney on November 6, 2023. (Photo by David Gray/AFP Photo)