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 man watches as high surf crashes into the wall and spills onto Channel Drive in Montecito, Calif., January 7, 2016. Bacteria levels can increase significantly during and after rainstorms as contaminants in the runoff enter the ocean via storm drains, creeks and rivers. (Photo by Mike Eliason/AP Photo)

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)

Pablo Holcer tests out a VR system made by Neurable that allows the user to control with their thoughts as the EEG headset interprets thoughts into actions in the VR environment at SIGGRAPH 2017 in Los Angeles, California, July 31, 2017. (Photo by Mike Blake/Reuters)

Model Georgia Salpa attends the UK Premiere of “A Good Day To Die Hard” at Empire Leicester Square on February 7, 2013 in London, England. (Photo by UK Press)

Giant Olympic rings are towed on The River Thames past The Tower of London on February 28, 2012 in London, England. (Photo by Peter Macdiarmid/Getty Images)

People run along a street as rain caused by tropical storm Alberto, the first named storm of 2024 Atlantic hurricane season, falls, in Monterrey, Mexico. on June 19, 2024. (Photo by Daniel Becerril/Reuters)

Japan's Naomi Osaka returns the ball during her match against Slovakia's Dominika Cibulkova during the Madrid Open tennis tournament, Sunday, May 5, 2019, in Madrid, Spain. (Photo by Andrea Comas/AP Photo)