Elise de Jong of Team Netherlands competes in the Women's Pole Vault during day two of the European Athletics U20 Championships 2025 on August 08, 2025 in Tampere, Finland. (Photo by Maja Hitij/Getty Images for European Athletics)

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.

Turkana tribesmen walk with guns to protect their cattle from rival tribes near Baragoy, Kenya August 4, 2017. (Photo by Goran Tomasevic/Reuters)

Canada's Leylah Fernandez serves against Croatia's Donna Vekic during their women's singles match at the United Cup tennis tournament in Perth on December 28, 2024. (Photo by Colin Murty/AFP Photo)

U.S. Air Force wounded warrior, Capt. Sarah Evans, jumps rope in a gym in San Antonio, Texas. Evans was diagnosed with cancer while deployed to Afghanistan and was medically evacuated back to the United States where her leg was amputated. (Photo by Master Sgt. Jeffrey Allen/U.S. Air Force)

“Misty Morning”. Every morning, people expect sunny weather. Photo location: Bali, Indonesia. (Photo and caption by Henry Adam/National Geographic Photo Contest)

Russian President Vladimir Putin (C) and Defence Minister Sergei Shoigu (back) attend a reception to honour graduates of military academies at the Kremlin in Moscow, Russia, June 28, 2016. (Photo by Alexei Druzhinin/Reuters/Sputnik/Kremlin)

Actress Laverne Cox attends The 59th GRAMMY Awards at STAPLES Center on February 12, 2017 in Los Angeles, California. (Photo by Christopher Polk/Getty Images for NARAS)