A chimpanzee relaxes in the shade at the Safari Park as the popular attraction prepares for the upcoming Jewish festival of Pesach (Passover) on April 14, 2008 in Ramat Gan near Tel Aviv, Israel. (Photo by David Silverman/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.

Miranda Kerr poses at the David Jones Spring/Summer fashion preview on Burke Street on August 10, 2011 in Melbourne, Australia. (Photo by Lucas Dawson)

Indonesian army soldier Partika Subagyo, wearing a costume of the puppet character Bima, dances to raise money for landslide victims, in Solo, December 17, 2014, in this photo taken by Antara Foto. The landslide in Banjarnegara destroyed a village and killed at least 32 people, according to officials. (Photo by Andika Betha/Reuters/Antara Foto)

Santiago Eneme (second left) and his Equatorial Guinea teammates can’t watch during their last 16 penalty shoot-out with Mali, although they did go on to win at Limbe Omnisport Stadium in Limbe, Cameroon on January 26, 2022. (Photo by Thaier Al-Sudani/Reuters)

Fishermen are seen near thousands of fish found dead at Lake Maninjau due to lack of oxygen levels at the bottom of the lake and bad weather that hit the area in Agam, West Sumatra Province, Indonesia on April 29, 2021. (Photo by Muhammad Arif Pribadi/Antara Foto via Reuters)

Cast member Yara Sophia of “RuPaul's Drag Race” visits the Empire State Building in New York City on June 24, 2021. (Photo by Stephen Lovekin/Rex Features/Shutterstock)

Chinese American actress Bai Ling arrives at the 58th Golden Horse Awards in Taipei, Taiwan, Saturday, November 27, 2021. Bai is a guest at this year's Golden Horse Awards, one of the Chinese-language film industry's biggest annual events. (Photo by Billy Dai/AP Photo)