A member of the Knights Guard cleans the ice during the Vegas Golden Knights' game against the Colorado Avalanche at T-Mobile Arena on April 28, 2021 in Las Vegas, Nevada. The Golden Knights defeated the Avalanche 5-2. (Photo by Ethan Miller/Getty Images via AFP Photo)

Relatives perform the last rites before the cremation of their loved one who died due to the Covid-19 coronavirus at a cremation ground in Allahabad on May 4, 2021. (Photo by Sanjay Kanojia/AFP Photo)

A seagull looks on as the Italian three-color special air force acrobatic team “Frecce Tricolori” flies over Rome and the Vatican Wednesday, June 2, 2021, as Italy celebrates the anniversary of its unification. (Photo by Andrew Medichini/AP Photo)

A model prepares backstage during the bridal fashion show as a part of Yes Wedding Expo at Convention Hall Tunjungan Plaza on June 13, 2021 in Surabaya, Indonesia. (Photo by Robertus Pudyanto/Getty Images)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

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.

Lightning strikes the Willis Tower (formerly Sears Tower) in downtown on June 12, 2013 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

Archie, a Chinese Crested dog, sits with his tongue out before the start of the 20th Annual Ugliest Dog Competition at the Sonoma-Marin Fair June 20, 2008 in Petaluma, California. Owners of ugly dogs travel to Petaluma from all over the country to participate in the annual contest. (Photo by Justin Sullivan/Getty Images)