Couple getting intimate on couch. (Photo by Vincent Besnault/Getty Images)

A reveller takes part in the “Free Parade” during LGBTIQ Pride Month in Porto Alegre, state of Rio Grande do Sul, Brazil on June 12, 2022. (Photo by Diego Vara/Reuters)

People enjoying the hot weather on Brighton beach in Sussex, England on August 7, 2020. (Photo by Stephen Lock/i-Images)

A demonstrator skateboards in front of a burning police vehicle during a protest against a new proposed policing bill, in Bristol, Britain, March 21, 2021. The Police, Crime, Sentencing and Courts Bill would give forces in England and Wales more power to impose conditions on non- violent protests, including those deemed too noisy or a nuisance, with fines or jail for those convicted. (Photo by Peter Cziborra/Reuters)

Belgian yoga teacher Dorien Dierckx, 29 from Brussels enjoys a beer while relaxing in a jacuzzi full of hot water and a mixture of ingredients used to make beer, and where customers can serve their own beer from the tap at the Good Beer Spa in Brussels, Belgium on May 12, 2021. (Photo by Yves Herman/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.

Visitors run away as waves caused by a tidal bore surge past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province August 13, 2014. (Photo by Reuters/Stringer)

A man wearing a water-filled helmet in which a goldfish swims performs an act titled “Aquaman” during the Night Festival 2016 in Singapore, 20 August 2016. The ninth edition of the festival will run from 19 to 27 August and features installations and performances by a range of international and local artists. (Photo by Wallace Woon/EPA)