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)

Camera trapper Xavier Hubert-Brierre put this large mirror on the side of a road through the jungle in Gabon and left a camera there to record how the animals would respond to their own reflections. A silverback gorilla thought it was seeing another silverback and responded by trying to scare off the potential challenger… (Photo by Xavier Hubert-Brierre/Johns Hopkins University Press)

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 Cobra JoyRide car charger by Cobra Electronics is displayed during a press event at The Venetian for the 2012 International Consumer Electronics Show (CES) January 8, 2012 in Las Vegas, Nevada. The JoyRide works with Android phones and can automatically trigger preset phone functions like enabling GPS or disabling Wi-Fi with the press of a single button. It will be available for USD 39 in the second quarter of 2012. (Photo by Ethan Miller/Getty Images)

In this Saturday, March 3, 2018, photo, a contestant gets ready to throw a hatchet at a wooden bull's-eye at the Kick Axe Throwing venue in the Brooklyn borough of New York. Kick Axe Throwing is the first bar in New York City to pick up on a nationwide trend of ax throwing, a growing sport that some enthusiasts hope will take off the way bowling did in the last century. (Photo by Mary Altaffer/AP Photo)

circa 1930: The neon illuminations of a wedding Chapel in Las Vegas.

Italy's Louis Phillip Vito III falls as he competes during the men's halfpipe qualification round at the 2022 Winter Olympics, Wednesday, February 9, 2022, in Zhangjiakou, China. (Photo by Francisco Seco/AP Photo)