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.

An injured young woman is led away after an incident at Parsons Green underground tube station in west London on September 15, 2017. Police and ambulance services said they were responding to an “incident” at Parsons Green underground station in west London on Friday, following media reports of an explosion. A Metro. co. uk reporter at the scene was quoted by the paper as saying that a white container exploded on the train and passengers had suffered facial burns. (Photo by Luke MacGregor/Reuters)

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

Opposition supporters march in the streets during a demonstration against the Ivorian President running for a third term in the next presidential elections, in Bonoua, Ivory Coast, 21 August 2020. The Ivorian opposition opposes a third term for incumbent president Ouattara who has been in power for ten years. The presidential elections will be held in October 2020. (Photo by Legnan Koula/EPA/EFE)

A red squirrel sniffs out nuts inside Christmas stockings as part of the festive celebrations and enrichment programme at Wildwood Escot Park in Ottery St Mary, Devon, United Kingdom on December 17, 2020. (Photo by Ben Birchall/PA Images via Getty Images)

A woman dancer prepare a performance during Nyepi celebration, the annual day of silence marking Balinese Hindu new year in Bali, Indonesia on Wednesday, March 2, 2022. Most Balinese practice self-reflection and stay at home to observe the quiet holiday, and tourists visiting the island are asked not to leave their hotels and the airport will be closed. (Photo by Firdia Lisnawati/AP Photo)

Jasmine Entz gets a kiss from her Guinness Book of World Record-breaking 8-year-old Holstein steer called “Beef”, who weighs 2,400 pounds and stands nearly two meters (6 feet) tall, on her ranch in Vulcan County, Alberta, Canada, on Friday, September 26, 2025. (Photo by Jeff McIntosh/The Canadian Press via AP Photo)

“Hiding In The Shadows”. This Baby Sandhill taking refuge under Moms wings while sitting on her second egg. I witnessed this baby being born earlier that day,and the next morning saw the other one hatch,what a sight to see. Photo location: Deland, Florida. (Photo and caption by Scott Helfrich/National Geographic Photo Contest)