Canoeists are framed by the tail of a breaching whale in Antarctica in April 2023. The photographer, from California, writes: “It was probably a once-in-a-lifetime moment”. (Photo by Jiahong Zeng/Solent News)

Judges watch athletes during the women's individual compact NH 5km competition at the Nordic Combined World Cup in Ramsau, Austria, Saturday, December 16, 2023. (Photo by Matthias Schrader/AP Photo)

A team from Woody's Ice Cream shop wrangle a large inflatable dinosaur down the street during the Independence Day Parade in Fairfax, Virginia July 4, 2015. Americans marched in star-spangled parades, ran relay races, gathered for fireworks shows and crowned a new world hot dog eating champion as they celebrated Independence Day in traditional style on Saturday. (Photo by Jonathan Ernst/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.

Elena Reid of USA looks on with bloody face due to a cut during the Women's WIBF Flyweight Championship fight between Regina Halmich and Elena Reid at the Boerderlandhalle on December 3, 2005 in Magdeburg, Germany. (Photo by Christian Fischer/Getty Images)

Second placed Kalex Moto2 Tito Rabat (rear R) of Spain and third placed Kalex Moto2 Alex Rins of Spain spray with champagne during the award ceremony for the Czech Grand Prix in Brno, Czech Republic, August 16, 2015. (Photo by David W. Cerny/Reuters)

Italy's Louis Phillip Vito III falls as he competes during the men's halfpipe qualification round at the 2022 Winter Olympics, Wednesday, February 9, 2022, in Zhangjiakou, China. (Photo by Francisco Seco/AP Photo)

Marta Garcia (R) of Spain loses the champgane bottle standing on the podium next to winner Jamie Chadwick of Great Britain after the first race of the W Series at Hockenheimring on May 04, 2019 in Hockenheim, Germany. W Series aims to give female drivers an opportunity in motorsport that hasn’t been available to them before. The first race of the series, which encompasses six rounds on the DTM support programme, is at the Hockenheimring on May 3rd and 4th. (Photo by Kai Pfaffenbach/Reuters)