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 woman wearing a face mask to help protect against the spread of the new coronavirus crosses a stream in Seoul, South Korea, Wednesday, July 15, 2020. (Photo by Lee Jin-man/AP Photo)

A competition, now in its 43rd year, dedicated to showcasing the beautiful and bizarre as seen under a light microscope attracted over 2,000 entries from 88 countries. Here: Honorable Mention by Emre Can Alagöz, Istanbul, Turkey: The eyes of a jumping spider, magnified 6x. (Photo by Emre Can Alagöz/2017 Nikon Small World Photomicrography Competition)

Young Korean women wearing hanbok (Korean traditional dress) walk inside Gyeongbok Palace on March 27, 2016 in Seoul, South Korea. There has been a trend in recent years for the young Koreans to wear the traditional Korean dress, Hanbok. Wearing the traditional dress, they will walk around downtown Seoul on weekends taking selfies, and share their memories with friends on social media, and also to promote their traditional dress to foreign visitors. (Photo by Jean Chung/Getty Images)

Members of the media touch a moving model of a Tyrannosaurus, which uses a dinosaur-type human-operated mechanical suit called “Dino-Techne” by Japanese firm On-Art, during a media preview of the Dinoa Live Exhibition / Amazing Dinosaur Art Exhibition in the Shinjuku district of Tokyo on December 10, 2020. (Photo by Philip Fong/AFP Photo)

A woman makes use of a still day on Inle Lake in Burma on January 16, 2020 by drying newly-dyed threads made out of lotus stems. (Photo by Sabina Akter/Solent News)

Fish are thrown onto a truck during a winter fishing festival held on the frozen Wulungu Lake in Fuhai county, Xinjiang Uighur Autonomous Region, January 18, 2015. (Photo by Reuters/China Daily)