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.

American actress, model, and singer Ashley Benson arrives at Paris Hilton's wedding party inBeverly Hills, CA. on November 14, 2021. (Photo by Backgrid USA)

(From L) Spanish actresses Aixa Villagran, Leticia Dolera and Celia Freijeiro pose on the pink carpet during the closing night of the 2019 Cannes International Series festival Canneseries, at the Palais des festival, in Cannes southern France, on April 10, 2019. (Photo by Valéry Hache/AFP Photo)

One of the most significant challenges related to cancer in Nepal is the lack of awareness around the prognosis of the disease, as many patients, their families and even healthcare professionals consider cancer to be an incurable disease at any stage. This results in significant delays in bringing patients to hospitals, and high rates of advanced stage cancers and mortality. (Photo by Omar Havana)

Take me away, deer, Russia. The Nenet people of Arctic Russia use reindeer and sledges as a prime mode of transport. The animals’ navigational ability means that in severe conditions they are sometimes the only hope of survival. (Photo by Kamil Nureev/Smithsonian Photo Contest)

In this January 27, 2020 photo, Jessica Hahn-Chaplin applies make up before a rehearsal of the Paraiso de Tuiuti samba school in Rio de Janeiro, Brazil. Hahn-Chaplin dances samba annually in Bath, England. (Photo by Silvia Izquierdo/AP Photo)

Pigeons fly out from the mouth of a giant Buddha statue at Wat Nam Daeng Buddhist temple in Chachoengsao province, east of the Thai capital Bangkok, on October 11, 2020. (Photo by Mladen Antonov/AFP Photo)