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.

United States Coast Guard Academy Cadets Second Class Aurimas Juodka, left, and Sheila Bertrand get in the face of “swab” Kevin Lennox as Bravo Company finishes at the barber shop and mailroom during R-Day, the reporting-in day that marks the beginning of the 7-week “Swab Summer” for the class of 2018 Monday, June 30, 2014, in New London, Conn. About 250 prospective cadets, Swabs, start the program designed to indoctrinate them to the military life of the academy and at the end will be accepted into the corps of cadets. (Photo by Sean D. Elliot/AP Photo/The Day)

Schoolchildren from local schools take part in the children's races prior to the annual Pancake race in Olney, Buckinghamshire, England, Tuesday, February 25, 2020. Every year women clad in aprons and head scarves from Olney and the city of Liberal, in Kansas, USA, run their respective legs of the race with pancakes in their pans. According to legend, the Olney race started in 1445 when a harried housewife arrived at church on Shrove Tuesday still clutching her frying pan with a pancake in it. (Photo by Alastair Grant/AP Photo)

Copperhead ridden by Harry Cobden falls during the RSA Insurance Novices' Chase (Grade 1) at Cheltenham Racecourse on March 11, 2020 in Cheltenham, England. (Photo by Tom Jenkins/The Guardian)

A general view of Copacabana beach during the coronavirus disease (COVID-19) outbreak in Rio de Janeiro, Brazil, March 22, 2020. (Photo by Ricardo Moraes/Reuters)

A municipality worker in a protective suit feeds street cats at Sultanahmet Square, as the spread of coronavirus disease (COVID-19) continues in Istanbul, Turkey, April 9, 2020. (Photo by Umit Bektas/Reuters)

Beesan al-Jubeh, (L), Palestinian under-10 national karate champion, trains with her father Sami (R) and other family members, all wearing face masks and gloves due to the COVID-19 coronavirus pandemic, outside their house in the city of Hebron in the Occupied West Bank on April 9, 2020. (Photo by Hazem Bader/AFP Photo)

Steven Busulwa, an animal keeper, runs away from a charging rhino at the Uganda Wildlife Conservation Education Center (UWEC) amid the lockdown as part of the measures taken to prevent the spread of the coronavirus disease (COVID-19), within Wakiso district, in Entebbe, Uganda on April 20, 2020. (Photo by Abubaker Lubowa/Reuters)