The digital art piece “Visor” by Mad Dog Jones is pictured ahead of an auction at Sotheby’s in London, United Kingdom on June 1, 2021. (Photo by Mad Dog Jones/Reuters)

A black-winged stilt patrols a reservoir in Jezreel Valley in Israel early April 2023. Their eggs are a golden colour mottled with brown. (Photo by Itamar Procaccia/Solent News)

Climate activists of the “Last Generation” covered with mud protest in front of the Senate building in Rome, Italy, Tuesday, May 23, 2023. Two bare breast activists have smeared the facade of the senate with mud, shouting the slogan: “Help us for the ecological transition”. (Photo by Cecilia Fabiano/LaPresse via EXPA)

Xabi Zurutuza of Spain for Red Bull KTM Ajo crashes during Moto3 Free Practice Three as part of the Australian Motorcycle Grand Prix at the Phillip Island Grand Prix Circuit in Phillip Island, Australia, 19 October 2024. (Photo by Joel Carrett/EPA)

Spain's #02 Tania Moreno Matveeva digs the ball in the women's round of 16 beach volleyball match between Spain and Netherlands during the Paris 2024 Olympic Games at the Eiffel Tower Stadium in Paris on August 5, 2024. (Photo by Aris Messinis/AFP Photo)

A “scissors” dancer grabs her shoe with her mouth while performing in a national scissors dance competition in the outskirts of Lima December 1, 2013. The Danza de las tijeras, or scissors dance, is a traditional dance from the Peruvian southern region of the Andes, in which two or more performers take turns dancing while accompanied with music from a harp and a violin. Dancers would display various skills and moves, which include cutting the air with the use of a scissors. (Photo by Enrique Castro-Mendivil/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.

A woman photographs “Super Space Titan Kitty” by Colin Christian at the “Hello! Exploring the Supercute World of Hello Kitty” museum exhibit in honor of Hello Kitty's 40th anniversary, at the Japanese American National Museum in Los Angeles, California October 10, 2014. (Photo by Lucy Nicholson/Reuters)