Water vapour cascades down the Gold Buddha Mountain after a rainfall, drawing large crowds of visitors, on May 13, 2024 in Chongqing, China. (Photo by Qu Mingbin/VCG via Getty Images)

Actress Violet McGraw, who played Cady in the film M3GAN, attends CinemaCon 2025 – Universal Pictures and Focus Features Invites You to a Special Presentation Featuring Footage from its Upcoming Slate at The Colosseum at Caesars Palace during CinemaCon, the official convention of Cinema United, on April 2, 2025, in Las Vegas, Nevada. (Photo by Alberto E. Rodriguez/Getty Images for CinemaCon)

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.

Men push a motorbike through a street flooded by a river that overflowed from heavy rains caused by Hurricane Matthew in Leogane, Haiti, Wednesday, October 5, 2016. Rescue workers in Haiti struggled to reach cutoff towns and learn the full extent of the death and destruction caused by Hurricane Matthew as the storm began battering the Bahamas on Wednesday and triggered large-scale evacuations along the U.S. East Coast. (Photo by Dieu Nalio Chery/AP Photo)

A Vietnamese bride is seen pushing the groom on a scooter during a photo shoot for their wedding in An Bang Beach outside Hoi An in Vietnam December 11, 2016. (Photo by Reuters/Stringer)

A Kashmiri Muslim bride looks through her veil during a mass wedding event in Srinagar, Indian controlled Kashmir, Thursday, June 15, 2023. Mass weddings in India are organized by social organizations primarily to help the economically backward families who cannot afford the high ceremony costs as well as the customary dowry and expensive gifts that are still prevalent in many communities. (Photo by Mukhtar Khan/AP Photo)

Members of Team Japan compete in the Artistic Swimming Team Acrobatic Final on day four of the Fukuoka 2023 World Aquatics Championships at Marine Messe Fukuoka Hall A on July 17, 2023 in Fukuoka, Japan. (Photo by Quinn Rooney/Getty Images)

Protesters, mainly Houthi supporters, hold posters showing the late Hamas leader Yahya Sinwar as they rally to show support to Lebanon's Hezbollah and Palestinians in the Gaza Strip, in Sanaa, Yemen on October 18, 2024. (Photo by Khaled Abdullah/Reuters)