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.

The newly-discovered gaseous planet Kepler-16b orbits it's two stars. NASA's Kepler Mission discoverd the world orbiting two Stars, the larger a K dwarf and the smaller a red dwarf. (Photo by NASA/JPL-Caltech/T. Pyle via Getty Images)

Rebecca Bailey rides a unicycle during a winter nor'easter snow storm in Boston, Massachusetts, U.S. February 9, 2017. (Photo by Brian Snyder/Reuters)

Caroline Wozniacki of Denmark serves to Alisa Kleybanova of Russia during the BNP Paribas Open at the Indian Wells Tennis Garden on March 15, 2011 in Indian Wells, California. (Photo by Matthew Stockman/Getty Images)

Using clever low exposure techinques, photographer Rolf Maeder managed to capture multiple strikes hitting the canyon under atmospheric stormy skies. (Photo by Rolf Maeder)

Models wait backstage prior to the Viktor&Rolf Spring-Summer 2022 Haute Couture fashion collection, in Paris, Wednesday, January 26, 2022. (Photo by Thibault Camus/AP Photo)

A pair of red junglefowl fight over territory in Pasir Ris Park, Singapore in the second decade of February 2025. (Photo by Liew Tong Leng/Solent News)