In this August 28, 1963 file photo, the top of the Washington Monument and part of a U.S. flag are reflected in the sunglasses of Austin Clinton Brown, 9, of Gainesville, Ga., as he poses at the Capitol where he joins others in the March on Washington. (Photo by AFP Photo)

US Maia Weintraub (L) and Japan's Sera Azuma compete during the Women's Team Foil event Bronze medal match, as part of the FIE Fencing World Championships at the Fair Allianz MI.CO (Milano Convegni) in Milan, on July 29, 2023. (Photo by Andreas Solaro/AFP Photo)

Zuo Tong of China performs on floor exercise during the women's team artistic gymnastics event of the 19th Asian Games in Hangzhou, China, Monday, September 25, 2023. China team won the gold. (Photo by Aaron Favila/AP Photo)

A wax figure of President William Howard Taft is seated in the front seat with his detached head in the back after it was purchased from an auction of the Hall of Presidents Museum, which closed in November, in Gettysburg, Pennsylvania, U.S. January 14, 2017. (Photo by Mark Makela/Reuters)

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.

Crocodile meat parts stands on display on Huangsha Seafood Market in Guangzhou, Guandong Province, China, 20 January 2018. Tsukiji Market of China or Huangsha Seafood Market is biggest one in Southern China and one of the biggest in China, as there are literally hundreds of different varieties of fish and seafood scattered throughout the market. (Photo by Aleksandar Plavevski/EPA/EFE)

Brides display their hands decorated with henna around a bride as she poses for her own photographer during a mass marriage ceremony in which, according to its organizers, 70 Muslim couples took their wedding vows, in Ahmedabad, India, February 11, 2018. (Photo by Amit Dave/Reuters)

Activists protesting cuts in subsidies to solar power in Germany protest outside the building where Vice Chancellor and Economy Minister Philipp Roesler and Environment Minister Norbert Roettgen were announcing the cuts on February 23, 2012 in Berlin, Germany. (Photo by Sean Gallup/Getty Images)