Members of the Uniao da Ilha do Governador Samba School perform during the first day of the Special Group Samba Schools parade of Carnival at the Sambadrome in Rio de Janeiro, Brazil, 07 February 2016. (Photo by Luiz Eduardo Perez/EPA)

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.

Canadian actress Ellen Page and wife Emma Portner arrive at “The Cured” – Los Angeles Special Screening on February 20, 2018 at AMC Dine-In Sunset 5 in West Hollywood, CA. (Photo by Parisa Michelle/Splash News and Pictures)

An influencer wearing a Barbie inspired dress walks at The Edge observation deck during sunrise on World Photography Day at The Edge at Hudson Yards on August 19, 2023 in New York City. The Edge at Hudson Yards opened for guests earlier than normal for a special World Photography Day Sunrise Event. (Photo by Alexi Rosenfeld/Getty Images)

Ceremonial skulls La Paz, Bolivia on November 6, 2020. Toads are in Bolivia symbols of the soil and of luck. They complement the Ñatitas, skulls of deceased people that are believed to have special powers. People ask them for different favours. The tradition is related to All Saints´ Day. (Photo by Radoslaw Czajkowski/Rex Features/Shutterstock)

Female military officers of Gendarmerie Special Public Security Command (JOAK) attend an exercise in Ankara, Turkey on March 6, 2020. Female gendarmeries give “There is nothing that a woman cannot achieve if she wants”. message with their difficult tasks ahead of the International Women's Day. (Photo by Mustafa Murat Kaynak/Anadolu Agency via Getty Images)

Fareeda, wife of Shameem Ahmad Ganai, who according to Fareeda was arrested during a clampdown a day before the scrapping of the special constitutional status in Kashmir by the government, tends to her husband's sheep in their house, in Pulwama, south of Srinagar, August 13, 2019. (Photo by Danish Siddiqui/Reuters)

Young children at a Bristol, Great Britain health centre unsure of the benefits of sun-lamps and the special glasses that must be worn, July 1948. The health centre was part of the newly introduced free National Health Service. (Photo by Popperfoto/Getty Images)