Athletes in action during the international parachuting competition Mountain Gravity in Quinto, Switzerland, 27 August 2015. Some 200 participants from all over the world are expected to jump at the event running from 22 to 30 August 2015. (Photo by Samuel Golay/EPA)

A Syrian man rides his bicycle past a man selling grains during a halt in fighting on February 29, 2016 in Douma, in the Eastern Ghouta region, east of the capital Damascus. A UN-backed ceasefire deal took hold across parts of Syria, bringing relative calm to areas where the Islamic State group and Al-Qaeda's local affiliate are not present. (Photo by Sameer Al-Doumy/AFP Photo)

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 competitor poses on the catwalk during the Miss Bumbum Brazil 2016 pageant in Sao Paulo, Brazil on November 9, 2016. Fifteen candidates compete in the annual pageant to select Brazil' s sexiest female rear end. (Photo by Miguel Schincariol/AFP Photo)

Residents of the Korean port of Inchon surrender to American troops. (Photo by Bert Hardy/Getty Images). 1950

Jimmy Arnold, an overweight boy from Rochester, bites into a cake. (Photo by Reg Birkett/Keystone/Getty Images). 14th April 1951

Britain's Emma Raducanu hits a return against Sloane Stephens of the US during their women's singles match on day two of the Australian Open tennis tournament in Melbourne on January 18, 2022. (Photo by James Gourley/Reuters)

Two Afghan children stand amid piles of garbage next to their home, in Kabul, Afghanistan, Monday, April 18, 2022. (Photo by Ebrahim Noroozi/AP Photo)