A man has an egg smashed on his head to raise money for charity during the World Egg Throwing Championships and Vintage Day in Swaton, Britain June 28, 2015. (Photo by Darren Staples/Reuters)

Participants re-enact the “Battle of Five Armies” from J.R.R. Tolkien's novel “The Hobbit” in a forest near the town of Doksy, Czech Republic June 6, 2015. According to event organizers, hundreds of enthusiasts dressed as characters such as elves, dwarves, goblins and orcs from the book “The Hobbit” re-enacted the clash. (Photo by David W. Cerny/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.

These girls are all smiles as they celebrate surviving A-level results day in Birmingham, England on August 15, 2019. The A Level is a subject-based qualification conferred as part of the General Certificate of Education, as well as a school leaving qualification offered by the educational bodies in the United Kingdom. (Photo by SnapperSK/SnapperMS)

Laura and Chris Marriott pose during a press photo call with their winning carrot at 3.8kg and Beetroot at 17.840kg following judging for the giant vegetable competition at the Harrogate Autumn Flower Show on September 13, 2019 in Harrogate, England. (Photo by Ian Forsyth/Getty Images)

Police officers arrest a protester during an anti-lockdown march in Liverpool, United Kingdom on November 21, 2020. The StandUpX movement organised a protest under the banner March for Freedom, Save Our City. (Photo by Mercury Press)

A jet ski is seen in Praia do Norte, Nazare, Portugal on January 9, 2023. (Photo by Pedro Nunes/Reuters)

Students participate in a wet t-shirt contest at the MTV Beach Bash party put on by Global Groove at the Bahia Mar Hotel during the annual ritual of Spring Break March 26, 2008 on South Padre Island, Texas. The South Texas island is one of the top Spring Break destinations and attracts students from all over the country. (Photo by Rick Gershon/Getty Images)