British band Florence and the Machine performs at the Bilbao BBK Live festival in Bilbao, Spain, early 13 July 2018. Bilbao BBK Live festival runs from 12 July to 14 July 2018. (Photo by Miguel Tona/EPA/EFE)

Girls sits on a bench during summer at the Central Park in New York, United States, 2011. (Photo by An Rong Xu)

A couple wearing masks as a precaution against the spread of the new coronavirus walk on the Malecon seawall at sunset in Havana, Cuba, Monday, August 31, 2020. Cuban authorities will introduce new measures starting tomorrow Tuesday aimed at containing the spread of the coronavirus in Havana among others a curfew from 7 pm until 5 am and no one without special permission will be able to enter or leave the province. The new measures will last at least 15 days. (Photo by Ramon Espinosa/AP Photo)

A pangolin carries its baby at a Bali zoo, Indonesia, Thursday, June 19, 2014. The pangolin baby was born on May 31. (Photo by Firdia Lisnawati/AP Photo)

Nihon University professor and head of Nihon University Animal Medical Center Kazuya Edamura, 49, points to cat photos on a computer screen, which are used to train the AI of “CatsMe!”, an AI-driven smartphone application jointly developed by tech startup Carelogy and researchers at Nihon University that purports to tell when a cat is feeling pain, as he gives a lecture to students on diagnosing pain in cats, at the medical center in Fujisawa, south of Tokyo, Japan on June 11, 2024. (Photo by Issei Kato/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.

Ahmad Sayed Rahman, a five-year-old Afghan boy who lost his right leg when he was hit by a bullet in the crossfire of a battle, dances with his prosthetic leg at the International Committee of the Red Cross (ICRC) hospital for war victims and the disabled, in Kabul on May 7, 2019. (Photo by Wakil Kohsar/AFP Photo)

Ivan, a tourist from Russia, takes a selfie at Mai Khao Beach as a plane takes off from Phuket International Airport in Phuket, Thailand, January 17, 2022. (Photo by Jorge Silva/Reuters)