Vendors sell their wares at a parking garage for commercial transports in Obalende district in Nigeria's commercial capital Lagos November 23, 2015. (Photo by Akintunde Akinleye/Reuters)

Monkeys eat fruits during the Monkey Buffet Festival, near the Phra Prang Sam Yot temple in Lopburi province, north of Bangkok, Thailand November 27, 2016. (Photo by Chaiwat Subprasom/Reuters)

Public Space series, 2015. This series by Morteza Niknahad and Behnam Zakeri tends toward cinema, taking an almost cartoonish view of modern life in Iran. This work was inspired by the social life of dolphins. (Photo by Morteza Niknahad and Behnam Zakeri/The Guardian)

Sеxy brunet striptease dancer dancing lap dance in front of man. (Photo by Blue SkyImages/Getty Images)

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.

Dawn at Blyth beach huts in Northumberland, with the prospect of warm weather over the coming weekend on Friday, October 8, 2021. (Photo by Owen Humphreys/PA Images via Getty Images)

German Yesakov, 25, a cameraman from Russia, dressed as movie character Captain Jack Sparrow, and his bride Anastasiya pose with a sailing ship decoration during their wedding ceremony in the southern city of Stavropol, Russia, February 5, 2016. Yesakov dressed as the Pirates of the Caribbean character and picked the film for the theme of his wedding as a surprise to his 17-year-old bride Anastasiya. (Photo by Eduard Korniyenko/Reuters)

Lightning streaks across the skies over the coastal port city of Batroun, some 43km north of the Lebanese capital Beirut on December 6, 2023. (Photo by Ibrahim Chalhoub/AFP Photo)