Indigenous nurses from the Special Secretariat for Indigenous Health (Sesai) of the Arapiuns ethnic group and Tapuia ethnic groups perform a rapid COVID-19 test on Chief Domingos from the Arapium tribe on the banks of the lower Tapajos River in the municipality of Santarem in western Para on July 19, 2020. (Photo by Tarso Sarraf/AFP Photo)

Members of the Apollo Rainbow Dancers stretch out in special A train late on May 4, 1985, in New York. The legendary Apollo Theatre celebrated its 50th anniversary in an official reopening after a 15 month refurbishing with a celebrity studded evening. (Photo by Ray Stubblebine/AP Photo)

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.

Canadian actress Ellen Page and wife Emma Portner arrive at “The Cured” – Los Angeles Special Screening on February 20, 2018 at AMC Dine-In Sunset 5 in West Hollywood, CA. (Photo by Parisa Michelle/Splash News and Pictures)

An Iraqi special forces soldier wears a rose in his body armor as troops move from the Yarmouk neighborhood to take another district from Islamic State militant control in Mosul, Iraq, Wednesday, April 12, 2017. (Photo by Maya Alleruzzo/AP Photo)

An influencer wearing a Barbie inspired dress walks at The Edge observation deck during sunrise on World Photography Day at The Edge at Hudson Yards on August 19, 2023 in New York City. The Edge at Hudson Yards opened for guests earlier than normal for a special World Photography Day Sunrise Event. (Photo by Alexi Rosenfeld/Getty Images)

Grave diggers wearing personal protective equipment (PPE) walk away after burying a person, who presumably died of the coronavirus disease (COVID-19), in the special purpose section of a graveyard on the outskirts of Saint Petersburg, Russia on May 13, 2020. (Photo by Anton Vaganov/Reuters)

A married couple is displayed on a pile of cheeses in the “Speciality” category during the Swiss Cheese Awards competition in Le Sentier, Switzerland September 23, 2016. One hundred and fourty-two experts have to choose the best out of 777 cheeses from 353 producers competing in 28 categories. (Photo by Denis Balibouse/Reuters)