Human like robots and robotic faces that mimic human expressions are displayed at the annual World Robot Conference at the Beijing Etrong International Exhibition and Convention Center in Beijing, Wednesday, August 16, 2023. (Photo by Ng Han Guan/AP Photo)

A man does physical exercise during sunset over the Finnish Gulf coast in St. Petersburg, Russia, Wednesday, April 14, 2021. (Photo by Dmitri Lovetsky/AP Photo)

Curvy queen Paloma Elsesser, second left, pictured with Bella Hadid, Adut Akech and Taylor Hill in the “Bras, That's Our Thing” campaign for the brand Victoria's Secret on February 17, 2023. (Photo by The Mega Agency)

Italy's Arianna Valcepina falls during the women's 500 m qualifying race at the ISU Short Track Speed Skating World Cup in Gdansk, Poland, 16 February 2024. (Photo by Adam Warzawa/EPA)

Laura Giombini of Italy reacts during the Women's Beach Volleyball preliminary round Pool D match against Jamie Lynn Broder and Kristina Valjas of Canada on Day 2 of the Rio 2016 Olympic Games at the Beach Volleyball Arena on August 7, 2016 in Rio de Janeiro, Brazil. (Photo by Shaun Botterill/Getty Images)

A machine engraves information on an ingot of 99.99 percent pure gold at the Krastsvetmet non-ferrous metals plant, one of the world's largest producers in the precious metals industry, in the Siberian city of Krasnoyarsk, Russia October 24, 2016. (Photo by Ilya Naymushin/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 model presents a creation for Kenzo by Japanese fashion designer Tomoaki Nagao aka Nigo during Kenzo fashion show at the North Bund Bay in Shanghai on July 28, 2023. (Photo by Jade Gao/AFP Photo)