A participant dressed up in a costume attends the 2021 Prague Comic Con in Prague, Czech Republic, October 16, 2021. (Photo by David W. Cerny/Reuters)

2016 Rio Olympics, Weightlifting, Final, Women's 63kg, Riocentro, Pavilion 2, Rio de Janeiro, Brazil on August 9, 2016. Marina Rodriguez (CUB) of Cuba competes. (Photo by Stoyan Nenov/Reuters)

2016 Rio Olympics, Judo, Final, Women, 48 kg Bronze Medal Contests, Carioca Arena 2, Rio de Janeiro, Brazil on August 6, 2016. Otgontsetseg Galbadrakh (KAZ) of Kazakhstan and Dayaris Mestre Alvarez (CUB) of Cuba react. (Photo by Kai Pfaffenbach/Reuters)

2016 Rio Olympics, Athletics, Final, Women's 200m Final, Olympic Stadium, Rio de Janeiro, Brazil on August 17, 2016. Photographers take pictures of Elaine Thompson (JAM) of Jamaica after she won the gold. (Photo by Gonzalo Fuentes/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.

Kyle Larson (42) flips as he makes contact with Jeffrey Earnhardt (81) on the back stretch during a NASCAR Cup Series auto race at Talladega Superspeedway, Sunday, April 28, 2019, in Talladega, Ala. (Photo by Greg McWilliams/AP Photo)

A runner in fancy dress attempts a record in the TCS London Marathon on Sunday, April 27, 2025. (Photo by John Sibley/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)