Bahamas' Shaunae Miller-Uibo celebrates winning the women's 200 meters final at the Diamond League Birmingham Grand Prix in Birmingham, Britain on August 18, 2019. (Photo by Jason Cairnduff/Action Images via 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)

Crowds watch surfers as the first big swell of the year arrives in Nazaré, Portugal on October 28, 2015. (Photo by Pedro Miranda/Demotix/Corbis)

Natalie Geisenberger of Germany, Johannes Ludwig of Germany, Tobias Wendl of Germany and Tobias Arlt of Germany celebrate their teammates slide winning gold during the Luge Team Relay on day six of the Beijing 2022 Winter Olympics at National Sliding Centre on February 10, 2022 in Yanqing, China. (Photo by Thomas Peter/Reuters)

Platense's defender Ayrton Costa (L) and River Plate's defender Andres Herrera vie for the ball during the Argentine Professional Football League match at the Monumental stadium in Buenos Aires, on October 12, 2022. (Photo by Juan Mabromata/AFP Photo)

Samba dancers arrive to perform ahead of the athletics competitions of the 2016 Summer Olympics at the Olympic stadium in Rio de Janeiro, Brazil, Sunday, August 14, 2016. (Photo by Jae C. Hong/AP Photo)

Paragliders fly towards the landing area of the “Acro Show” above Lake Geneva in Villeneuve, Switzerland on Sunday, August 26, 2018. (Photo by Valentin Flauraud/Keystone via AP Photo)