Carrion crows sit on poles around a field on the outskirts of Frankfurt, Germany, early Monday, June 26, 2023. (Photo by Michael Probst/AP Photo)

Performers take part in the opening ceremony for the Commonwealth Games at the Alexander Stadium in Birmingham, central England, on July 28, 2022. (Photo by Jason Cairnduff/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.

The aerial view shows three uprooted trees at a road near Hildesheim, Germany Friday, October 6, 2017. Seven people died Thursday as high winds knocked over trees and caused widespread travel chaos in northern Germany. (Photo by Julian Stratenschulte/DPA via AP Photo)

Jimmy Arnold, an overweight boy from Rochester, bites into a cake. (Photo by Reg Birkett/Keystone/Getty Images). 14th April 1951

Protesters carry a giant old Belarusian national flag during a Belarusian opposition supporters' rally protesting the official presidential election results in Minsk, Belarus, Sunday, September 13, 2020. Belarusians have been demonstrating against the disputed re-election of President Alexander Lukashenko for a month, with more than 100,000 people flooding the streets of Minsk for four straight weekends. (Photo by TUT.by via AP Photo)

Actor Howard Coggins performs during the Living Spits Beauty and the Beast comedy at the Bristol Old Vic on December 9, 2020 in Bristol, England. Living Spit stars Howard Coggins and Stu McLoughlin will perform Beauty and the Beast in a series of live broadcasts and on stage shows at the Old Vic from December 18. (Photo by Matthew Horwood/Getty Images)