2016 Rio Olympics, Athletics, Final, Women's 200m Final, Olympic Stadium, Rio de Janeiro, Brazil on August 17, 2016. Photographers take pictures of Elaine Thompson (JAM) of Jamaica after she won the gold. (Photo by Gonzalo Fuentes/Reuters)

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.

A team from Woody's Ice Cream shop wrangle a large inflatable dinosaur down the street during the Independence Day Parade in Fairfax, Virginia July 4, 2015. Americans marched in star-spangled parades, ran relay races, gathered for fireworks shows and crowned a new world hot dog eating champion as they celebrated Independence Day in traditional style on Saturday. (Photo by Jonathan Ernst/Reuters)

Japan's Naomi Osaka sits with her towel over her head during a break in her third round loss to Coco Gauff of the U.S. at the Australian Open tennis championship in Melbourne, Australia, Friday, January 24, 2020. (Photo by Lee Jin-man/AP Photo)

Models wait backstage ahead of the Carolina Herrera Fall/Winter 2023 collection show during the New York Fashion Week in New York City, U.S., February 13, 2023. (Photo by Andrew Kelly/Reuters)

British singer-songwriter Rita Ora has her knickers in a twist as she gets animated backstage at a music festival in Lithuania in the last decade of July 2024. (Photo by Splash News and Pictures)

The USA’s Beatriz Hatz competes at Women's Long Jump -T64 final at the Stade de France stadium, during the 2024 Paralympics, Saturday, August 31, 2024, in Paris, France. (Photo by Ümit Bektaş/Reuters)

Ecuador's Ronald Zabala G., riding, Forever Young Wundermaske, fall off their horse during the Equestrian Cross Country competition at Chateau de Versailles for the 2024 Summer Olympics, Sunday, July 28, 2024, in Versailles, France. (Photo by Mosa'ab Elshamy/AP Photo)