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.

Indian School children's in a traditational attire of a characters of Indian epic Ramayan, on the eve of children's day celebration at cubbon park, in Bangalore, India, 13 November 2016. Children's day (also known as Bal Divas), in India is celebrated every year on 14th of November to increase the awareness of people towards the rights, care, and education of children. Many schools hold activities and allow students to have fun and attend their classes in coloured dresses. (Photo by Jagadeesh N.V./EPA)

A workman smooths out the gravel near the base of British artist Alex Chinneck' latest sculpture “A bullet from a shooting star” on the Greenwich Peninsula in London on September 17, 2015. The 35-metre tall, upside-down electricity pylon overlooks the Canary Wharf financial district. (Photo by Leon Neal/AFP Photo)

Traffic police stand at the side of a road in Pyongyang on November 25, 2016. (Photo by Ed Jones/AFP Photo)

Law enforcement officers detain a man during a rally in support of jailed Russian opposition leader Alexei Navalny in Moscow, Russia on January 31, 2021. Thousands of people have taken to the streets across Russia to demand the release of jailed opposition leader Alexei Navalny, keeping up the wave of nationwide protests that have rattled the Kremlin. Hundreds have been detained by police. (Photo by Maxim Shemetov/Reuters)

A participant in the “Cats Who Look Like Cows” competition wears a cowboy outfit back stage before judging on March 05, 2023 in Bangkok, Thailand. Thailand's Cat Fanciers' Club hosted a “Cats Who Look Like Cows” competition during a Cat Expo in Bangkok's Ladphro neighborhood. Over 100 cats were judged on how similarly their pattern resembled a cow, color, fur softness and personality. A relaxed, fluffy cat named Arpo took home first prize. (Photo by Lauren DeCicca/Getty Images)

A ballerina from Kyiv City ballet prepares in the wings on stage during the opening night gala performance at The Theatre Royal in Bath, Britain on April 16, 2023. (Photo by Lee Smith/Reuters)

A dog at the Zoozashchita-NN veterinary clinic in Nizhny Novgorod, Russia on February 19, 2021. On February 13, 13 stray dogs with bright blue fur were found and caught at the Dzerzhinskoye Steklo (Dzerzhinsk Glass) factory producing acrylic glass and prussic acid in the city of Dzerzhinsk. The dogs' fur tested positive for the Prussian blue pigment; now the dogs are under supervision at the Zoozashchita-NN vet clinic in Nizhny Novgorod. (Photo by Mikhail Solunin/TASS)