Female Iraqi Kurdish peshmerga fighters watch on as they release a bear into the wild in the Gara Mountains near the northern Iraqi city of Dohuk on March 4, 2018, after Iraqi Kurdish Animal rights activists from a local NGO rescued it from a private home. (Photo by Safin Hamed/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.

With the help of some fake teeth and multiple exposures, New York AP photographer Eddie Adams' daughter Susan is transformed into a little ghoul on Halloween night, October 31, 1966. (Photo by Eddie Adams/AP Photo)

Wearing a Foo Fighters mask, Philadelphia Flyers goaltender Carter Hart heads back to his net after giving up a goal to the Boston Bruins during the third period at TD Garden, in Boston, Massachusetts on Thursday, November 17, 2022. (Photo by Winslow Townson/USA TODAY Sports)

A dancer warms up along 34th Street while waiting to perform during a pre-taping of the Macy's Thanksgiving Day Parade in front of the flagship store in New York, Wednesday, November 25, 2020. (Photo by Mary Altaffer/AP Photo)

A photo made avialable on 05 August 2015 shows an Indian woman collecting drinking water from a water pump in the submerged village of Sreerampur, some 150 kilometers north of Calcutta, India, on 04 August 2015. At least 215 people have died in floods and a landslide following monsoon rains in India over the past week, 83 deaths were reported from the western state of Gujarat and 69 from eastern West Bengal. The worst-affected states were West Bengal, Gujarat and Rajasthan, the Home Ministry said. (Photo by Piyal Adhikary/EPA)

A police officer wields his baton against a man as a punishment for defied curfew due to rise of COVID-19 coronavirus cases in Nagaon District of Assam, India on May 16, 2021. (Photo by Anuwar Hazarika/NurPhoto via Getty Images)

Antonio Banderas attends the photocall for “Pain And Glory (Dolor Y Gloria/Douleur Et Glorie)” during the 72nd annual Cannes Film Festival on May 18, 2019 in Cannes, France. (Photo by Pascal Le Segretain/Getty Images)