Some 1200 windsurfers take the start of the 21th edition of the Defi Wind in the Mediterranean Sea, off the coast of Gruissan in southern France, on May 19, 2023. (Photo by Charly Triballeau/AFP Photo)

A robot takes part in what is billed as the world's first robot half marathon during the Humanoid Robot Half-Marathon held in Beijing on Saturday, April 19, 2025. (Photo by Ng Han Guan/AP Photo)

Hollywood actress Malin Akerman helps King Digital Entertainment set the Guinness World Record for the World's Largest Hammock to celebrate the launch of its new game Paradise Bay on Wednesday, September 2, 2015, in Jersey City, N.J. (Photo by Charles Sykes/Invision for King World Entertainment/AP Images)

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.

Residents watch volcanic smoking and ashes rising from Mount Sinabung during an eruption in Karo, North Sumatra, Indonesia, February 24, 2016. Authorities have repeatedly called on local residents to remain patient in dealing with the impact of Sinabung's eruptions, which some experts have predicted will continue for five more years. (Photo by Xinhua/Barcroft Media)

More than 1,200 vintage posters that would send any movie buff into orbit were discovered in an Ohio garage, including the only known copy of an almost 7-foot-tall creation for the 1947 reissue of “Dracula” that could sell for $40,000. The Dallas-based Heritage Auctions in Dallas puts them all on the block March 22 and 23, including some rare specimens from the silent movie era. (Photo by Courtesy Heritage Auctions)

A dancer poses for her own photographer in front of pink cherry tree blossoms during a sunny spring morning at the Parc de Sceaux gardens near Paris, France, April 12, 2019. (Photo by Christian Hartmann/Reuters)

In this handout provided by the National Aeronautics and Space Administration (NASA), SpaceX's Falcon 9 is moved to the launch pad prior to the rocket's Thales Alenia Space launch attempt on April 26, 2015 in Cape Canaveral, Florida. (Photo by NASA via Getty Images)