A full moon is seen behind buildings at night in Ashkelon, southern Israel on December 1, 2020. (Photo by Amir Cohen/Reuters)

Storm clouds build over a canola field near Cremona, Alberta, Friday, July 29, 2022. (Photo by Jeff McIntosh/The Canadian Press via AP Photo)

Bowden Loch, near Melrose, Scottish Borders, Scotland. The Northern Lights made an appearance over the Uk on the evening of the 7th October 2024. (Photo by Phil Wilkinson/The Times)

A burned vehicle sits among a destroyed home in the Mountain fire, Wednesday, November 6, 2024, near Camarillo, Calif. (Photo by Ethan Swope/AP Photo)

A visitor takes a selfie with a backdrop of sunflowers in full bloom at the E-World Sunflower Garden in Daegu, 237 kilometers southeast of Seoul, South Korea, 13 July 2024. (Photo by Yonhap/EPA)

A small flock of birds seems to be giving an escort to an airliner on final approach to Reagan Washington National Airport in Arlington, Virginia on January 12, 2022. The scene took place over Gravelly Point which is an area within the National Park Service's George Washington Memorial Parkway. (Photo by Michael S. Williamson/The Washington Post)

An eight-year-old St Bernard with the longest canine tongue in the world, measuring 18.58cm (7.31in) in length, as recorded by the Guinness World Records: Amazing Animals, in South Dakota, USA. (Photo by Kevin Scott Ramos/GWR/PA Wire)

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.