A protester in an Elmo mask dances during the Justice for George Floyd Philadelphia Protest on Saturday, May 30, 2020. Demonstrators took to the streets across the United States to protest the death of Floyd, a black man who was killed in police custody in Minneapolis on May 25. (Photo by Matt Rourke/AP Photo)

People take turns stomping the Christopher Columbus statue after it was toppled in front of the Minnesota State Capitol in St. Paul, Minn., on Wednesday, June 10, 2020. (Photo by Leila Navidi/Star Tribune via AP Photo)

The new Citroen Concept Car Divine DS is presented at the 2014 Paris Auto Show on October 2, 2014 in Paris on the first of the two press days. European carmakers are hoping to impress with new models at this week's Paris Motor Show and prove they have come out stronger from years of economic trouble and cost-cutting. (Photo by Miguel Medina/AFP Photo)

A man holds on a rope as he tries to board a truck while crossing floodwaters brought by typhoon Koppu that battered Candaba town, Pampanga province, north of Manila October 20, 2015. Typhoon Koppu swept across the northern Philippines killing at least nine people as trees, power lines and walls were toppled and flood waters spread far from riverbeds, but tens of thousands of people were evacuated in time. (Photo by Romeo Ranoco/Reuters)

A model waits backstage to present creations from the Fall-Winter 2021/2022 collection of the Georgiela Studio fashion brand during a young talents “EGO” fashion show on the last day of the 73rd Mercedes-Benz Fashion Week Madrid, in Madrid, Spain, 11 April 2021. The fashion event runs from 08 to 11 April. (Photo by Mariscal/EPA/EFE)

Yakelin Hernandez, 18, poses for a photograph near The Malecon where The Carnival was held, on August 14, 2015. Colorful costumes, dancing, parades and street parties on the Malecon in Havana, Cuba are all part of Havana Carnival 2015 which was held in August. (Photo by Sarah L. Voisin/The Washington Post)

Several beaches along South Florida's Atlantic coast line were closed after thousands of sharks were seen migrating in the waters. The sharks were migrating from Boca Raton to Jupiter since the beginning of March, marine biologists told NBC Miami. Photo: A spinner shark swims just offshore on Midtown Beach in Palm Beach on Tuesday. (Photo by Jeffrey Langlois/Palm Beach Daily News)

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.