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.

Participants prepare backstage before the 5th “Strongo Cup” open amateur bodybuilding tournament at the State Opera and Ballet Theatre in Russia's Siberian city of Krasnoyarsk, November 1, 2014. Participants from all over Russia took part in the tournament competing in bodybuilding, body fitness and bikini fitness disciplines. (Photo by Ilya Naymushin/Reuters)

Stranded cars remain in a flooded street during an intense rainstorm in Havana, on April 29, 2015. Two people were killed, three buildings collapsed and another 24 suffered some kind of damage due to the heavy rain that affected several sectors of Havana Wednesday. (Photo by Yamil Lage/AFP Photo)

Poland's Adrian Meronk, left, celebrates with his partner Melania Bobrowicz during the Australian Open golf championship at Victoria golf course in Melbourne, Australia, Sunday, December 4, 2022. (Photo by Asanka Brendon Ratnayake/AP Photo)

British model Iris Law arrives at The Fashion Awards 2019 held at Royal Albert Hall on December 02, 2019 in London, England. (Photo by Lisi Niesner/Reuters)

Zendaya arrives at the 25th Annual Critics' Choice Awards at Barker Hangar on January 12, 2020 in Santa Monica, California. (Photo by Danny Moloshok/Reuters)

A protester poses for photos next to a burning police vehicle in Los Angeles, Saturday, May 30, 2020, during a demonstration over the death of George Floyd. a black man who was killed in police custody in Minneapolis on May 25. (Photo by Ringo H.W. Chiu/AP Photo)

A demonstrator is detained by police officers during clashes in downtown Barcelona, Spain, Friday, October 30, 2020. Clashes have erupted in a central Barcelona square between anti-riot police and hundreds who had gathered to protest the mandatory closure of bars, restaurants and other businesses in the latest effort to rein in on coronavirus outbreaks. (Photo by Joan Mateu/AP Photo)