Models wait backstage during the Ukrainian Fashion Week in Kiev, October 16, 2015. (Photo by Valentyn Ogirenko/Reuters)

F/A-18 fighter jet takes off from the USS Harry S. Truman aircraft carrier in the eastern Mediterranean Sea June 13, 2016. (Photo by Baz Ratner/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.

An young Indian Jain devotee dressed as Lord Krishna participates in a religious rally organised on the occasion of Mahavir Jayanti in Kolkata on April 2, 2015. The most important religious holiday in Jainism, Mahavir Jayanti celebrates the birth of Mahavira, the last Tirthankara, which is generally accepted as 599 BCE. (Photo by Dibyangshu Sarkar/AFP Photo)

This image released by Twentieth Century Fox shows Kristen Stewart in a scene from “Underwater”. (Photo by Alan Markfield/Twentieth Century Fox via AP Photo)

“A Cornish pasty, sometimes known as a pastie or British pasty in the United States, is a filled pastry case, associated in particular with Cornwall in Great Britain. It is made by placing the uncooked filling on a flat pastry circle, and folding it to wrap the filling, crimping the edge at the side or top to form a seal. The result is a raised semicircular package”. – Wikipedia

Photo: Cornish students (R) Nina Brooke, 21 and (L) Bonnie Mably, 20, laugh as they pose for a photograph as they try a Cornish pasty that has been baked as part of the World Cornish Pasty Championships at The Eden Project on March 3, 2012 in St Austell, England. (Photo by Matt Cardy/Getty Images)

American film director Mike Todd and his actress wife Elizabeth Taylor get into a spat after missing their flight from London to Nice on June 22, 1957. (Photo by AP Photo)