A member of the “Exit Point” amateur rope-jumping group jumps from a 44-metre high (144-ft) waterpipe bridge in the Siberian Taiga area outside Krasnoyarsk, November 3, 2013. Fans of rope-jumping, a kind of extreme sport involving a jump from a high point using an advanced leverage system combining mountaineering and rope safety equipment, marked the end of the group's jumping season and recent Halloween festivities. (Photo by Ilya Naymushin/Reuters)

Aimee, 19, who has Down syndrome, has make-up applied by her mother before a presentation in Monterrey, Mexico, in this picture taken April 9, 2016. The association “Abrazame con Discapacidad” (“Embrace me with Disabilities”) teaches folk dance to low-income people with Down syndrome and manages presentations at public events where they receive a payment, as part of a therapy that helps improve their motor system, learning and self-esteem, the association said. (Photo by Daniel Becerril/Reuters)

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 handout picture made available by the National Aeronautics and Space Administration (NASA) shows, NASA teams working around Boeing’s CST-100 Starliner spacecraft after it landed at White Sands Missile Range’s Space Harbor, in Las Cruces, New Mexico, 25 May 2022. Boeing’s Orbital Flight Test-2 (OFT-2) is Starliner’s second uncrewed flight test to the International Space Station as part of NASA's Commercial Crew Program. OFT-2 serves as an end-to-end test of the system's capabilities. (Photo by Bill Ingalls/NASA/EPA/EFE)

Palestinian groom Mohamed abu Daga and his bride Israa wear face masks amid the COVID-19 epidemic, during a photoshoot at a studio before their wedding ceremony in Khan Yunis in the southern Gaza Strip, on March 23, 2020. Authorities in Gaza confirmed on March 22 the first two cases of novel coronavirus, identifying them as Palestinians who had travelled to Pakistan and were being held in quarantine since their return, as the United Nations warned of potential disastrous outcomes to an outbreak given the high poverty rates and weak health system in the coastal strip, under Israeli blockade since 2007. (Photo by Said Khatib/AFP Photo)

People take part in a protest outside the Department for Education, London, Sunday August 16, 2020, in response to the A-level results. The British government has been urged to “get a grip” over how grades are being awarded to school students, who were unable to take exams earlier this summer because of the coronavirus pandemic. The latest confusion emerged late Saturday when England’s exam regulator launched a review on its own just-published guidance on how students can appeal grades awarded under a complicated system. (Photo by London News Pictures/The Sun)

A picture made available on 14 July 2016 shows Greyhound dogs racing at the Wentworth Park Stadium in Sydney, New South Wales (NSW), Australia, 13 July 2016. Greyhound racing has returned to Sydney's Wentworth Park and other NSW tracks for the first time since the state government announced plans to ban it. NSW Premier Mike Baird announced last week plans to shut down the sport in NSW following a Special Commission of Inquiry report that found “chilling” evidence of systemic animal cruelty within the industry. (Photo by David Moir/EPA)