Hotel guides jump as they pose for pictures outside the Great Hall of the People during the opening session of the National People's Congress (NPC) in Beijing, China, March 5, 2016. (Photo by Aly Song/Reuters)

Praia du Forte, Bahia. “This was the lead picture for a National Geographic story on Bahia, because it was both mysterious as well as a “geography” picture showing where the slaves arrived from Nigeria. Beach pictures seem like they should be easy to take, but for me they are actually quite difficult. Too easy to fall into cliche. When I saw the kid coming on the horse, I quickly ran to see if I could make something with a woman in a bikini that was not a bikini shot”. (Photo by David Alan Harvey/The Guardian)

Participants with traditional Japanese tattoos (Irezumi), related to the Yakuza, walk through the Asakusa district during the annual Sanja Matsuri festival in Tokyo on May 20, 2018. Sanja Matsuri festival is a celebration for the three founders of Sensoji Temple in the Asakusa neighbourhood with nearly two million people visiting during the three-day event. (Photo by Behrouz Mehri/AFP Photo)

Partygoers in Cardiff, England refused to let the rain dampen their Christmas spirits on “Thirsty Thursday”, December 19, 2018. Christmas partygoers got into the party spirit last night as they headed out for some festive fun up and down the country. (Photo by Huw Evans Picture Agency)

Kylie Jenner shows off a lot of cleavage in these new photos added to her Snapchat account on Thursday, August 25, 2016. Something that a lot of the 19-year-old reality star's fans pointed out was that her breasts looked larger than normal and she took to Twitter to explain why. Kylie said that she has “never” gotten her breasts done and that they look large because “it's that time of the month”. She even offered to let a fan feel them to prove that they are real! “They will deflate soon. And it will be a sad sad day”, Kylie added. (Photo by Scope Features)

A child reacts as a family takes a break next to a cooling mist at the Sensoji temple as Japanese government issued heat stroke alerts in 39 of the country's 47 prefectures in Tokyo, Japan on July 22, 2024. (Photo by Issei Kato/Reuters)

MSP Ash Regan and Lexie take part in Holyrood Dog of the Year on June 26, 2023 in Edinburgh, Scotland. At the annual contest, jointly organised by the Kennel Club and Dogs Trust, members of the Scottish Parliament compete with their dogs and Dogs Trust rescue dogs for the title of “Holyrood Dog of the Year”. (Photo by Jeff J. Mitchell/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.