Nyibol Lual, 13 years old, helps her family to prepare the land for cultivation on May 31, 2017, in Panthau, Northern Bahr al Ghazal, South Sudan. The family has a small land where they cultivate sorghum. An estimated 63 per cent of the population in Northern Bahr al Ghazal is experiencing severe food insecurity, according to the latest Integrated Food Security Phase Classification (IPC) report. The situation is particularly bad in Aweil West and Aweil South counties, where the exhaustion of household food stocks and growing dependence on financially inaccessible markets have left the population facing Emergency levels of food insecurity. (Photo by Albert Gonzalez Farran/AFP Photo)

Jesse Larios, 33, from Los Angeles, wears a bear suit while walking along Hollister Road in Gilroy, California, U.S., April 21, 2021. Larios, also known as Bear Sun on social media, is walking from his home in Los Angeles to San Francisco while wearing the bear suit as a social media fundraising event. (Photo by Brittany Hosea-Small/Reuters)

A demolition company explodes the support beams and columns in the roof of the Deutschlandhalle event location on December 3, 2011 in Berlin, Germany. (Photo by Adam Berry/Getty Images)

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.

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

An officer from the California Department of Fish and Wildlife gets ready to tranquillize a bear in Pasadena, California, U.S., August 20, 2021. (Photo by Mario Anzuoni/Reuters)

A fan of K-pop idol boy band BTS poses for photographs with cut-out of BTS at a pop-up store selling BTS goods in Seoul, South Korea, December 24, 2019. (Photo by Kim Hong-Ji/Reuters)

A house along Hoover Beach is covered by ice from high winds and from the waves from Lake Erie, Saturday, February 29, 2020, in Hamburg N.Y. Blowing snow has fallen around the state since Thursday, though the heaviest snowfall was concentrated in largely rural areas east of Lake Erie and Lake Ontario. (Photo by Jeffrey T. Barnes/AP Photo)