Pupils wearing face masks wait for the opening of their primary school on the first day of the new school year, in Ouagadougou, on October 1, 2020. (Photo by Olympia de Maismont/AFP Photo)

New York Yankees' Domingo Germán, center, is doused by teammates after he pitched a perfect game against the Oakland Athletics in a baseball game in Oakland, Calif., Wednesday, June 28, 2023. The Yankees won 11-0. (Photo by Godofredo A. Vásquez/AP Photo)

Nasoin Akhter, 15, has her makeup done at a beauty parlor on the day of her wedding to a 32-year-old man, August 20, 2015, in Manikganj, Bangladesh. In June of this year, Human Rights Watch released a damning report about child marriage in Bangladesh. The country has one of the highest rates of child marriage in the world, with 29% of girls marrying before the age of 15, and 65% of girls marrying before they turn 18. (Photo by Allison Joyce/Getty Images)

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.

Natalie Dormer attends the mtvU Fandom Awards at MTV Fan Fest at Comic-Con, July 24, 2014, in San Diego. (Photo by Jordan Strauss/Invision for MTV/AP Images)

Opposition supporters march in the streets during a demonstration against the Ivorian President running for a third term in the next presidential elections, in Bonoua, Ivory Coast, 21 August 2020. The Ivorian opposition opposes a third term for incumbent president Ouattara who has been in power for ten years. The presidential elections will be held in October 2020. (Photo by Legnan Koula/EPA/EFE)

A red squirrel sniffs out nuts inside Christmas stockings as part of the festive celebrations and enrichment programme at Wildwood Escot Park in Ottery St Mary, Devon, United Kingdom on December 17, 2020. (Photo by Ben Birchall/PA Images via Getty Images)

A woman dancer prepare a performance during Nyepi celebration, the annual day of silence marking Balinese Hindu new year in Bali, Indonesia on Wednesday, March 2, 2022. Most Balinese practice self-reflection and stay at home to observe the quiet holiday, and tourists visiting the island are asked not to leave their hotels and the airport will be closed. (Photo by Firdia Lisnawati/AP Photo)