David Sharp, an engineer with Lockheed Martin, displays the “Samurai Flyer”, an aviation design inspired by the maple seed, during the Association for Unmanned Vehicle Systems International Conference August 16, 2011 in Washington, DC. Lockheed Martin unveiled the new design and demonstrated vertical takeoff and landing, stable hover, and on-board video streaming of the aircraft during their demonstration. (Photo by Win McNamee/Getty 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.

Traditional dancers are seen at Ela Beach, near a venue of the Asia-Pacific Economic Cooperation (APEC) summit in Port Moresby, Papua New Guinea, 13 November 2018. The APEC summit brings together world leaders from its 21 member nations and is being hosted for the first time by Papua New Guinea. (Photo by Mast Irham/EPA/EFE)

A pair of foxes seem happy to see each other in Zandvoort, the Netherlands in the last decade of September 2024. (Photo by Anna Stelloo/Solent News)

Festival goers blow soap-bubbles at the 28th Sziget (Island) Festival on Shipyard Island, Northern Budapest, Hungary, 15 August 2022. The festival is one of the biggest cultural events of Europe offering art exhibitions, theatrical and circus performances and above all music concerts. (Photo by Marton Monus/EPA/EFE)

A woman pulls a wooden craft carrying her family in flood water after attending a wedding ceremony in Cilacap, Central Java, Indonesia, March 16, 2022. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

American singer-songwriter Taylor Swift performs onstage during Taylor Swift | The Eras Tour at Levi's Stadium on July 28, 2023 in Santa Clara, California. (Photo by Jeff Kravitz/TAS23/Getty Images for TAS Rights Management)

A walrus kisses a visitor during a sea animal show at the Hakkeijima Sea Paradise aquarium-amusement park complex in Yokohama, southwest of Tokyo, Monday, September 11, 2017. (Photo by Shizuo Kambayashi/AP Photo)