Satrio smokes at a kiosk after elementary school on March 3, 2017 in Yogyakarta, Indonesia. Satrio has smoked up to one pack a day and began when he was six years old. (Photo by Ulet Ifansasti/Getty Images)

Christopher Walken, Angelo Galasso and Clint Eastwood attend the premiere of Jersey Boys in New York June 9, 2014. REUTERS/Andrew Kelly

14th Place. Leaf roller weevil (Byctiscus betulae) lateral view. Image Stacking, Reflected Light 3.7X (objective lens magnification). (Photo by Özgür Kerem Bulur/Nikon Small World Photomicrography 2020)

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.

Third place: the rear leg, claw and respiratory trachea of a louse (Haematopinus suis). (Photo by Frank Reiser/Nassau Community College/Nikon Small World Photomicrography 2021)

Kim Kardashian looks to have left her underwear at home as she heads out for an early dinner with boyfriend Kanye West in Miami on October 14, 2012. As Kim checked out her outfit in the reflection of her car, it became apparent that the reality star was not wearing any underwear as she showed off her see-through grey skirt. (Photo by Brett Kaffee/Thibault Monnier/PacificCoastNews.com)

Children sit under a crocodile based table, as they pose for photographers during a press preview of a themed auction that features the animal as artistic inspiration, entitled “Creatures Great and Small”, in London, Monday, December 15, 2014. The sale scheduled for December 17, 2014, explores animals across a diverse range of mediums and styles, from intricate carving details in 19th century furniture through to contemporary sculpture, according to Christie’s auction house. (Photo by Lefteris Pitarakis/AP Photo)