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)

Donald Trump is flanked by Playmates at a party celebrating Playboy magazine's 45th anniversary at the Life Club in New York on December 3, 1998. (Photo by Richard Corkery/NY Daily News Archive via Getty Images)

This photo taken on January 28, 2018 shows participants taking part in games on stage during the “&Proud” LGBT festival in Yangon. Races, games, music and fun were just some of the highlights of the “&Proud” LGBT festival, which took place in a Yangon public park for the first time at the weekend in a country where same-s*x relations are still officially illegal. (Photo by Ye Aung Thu/AFP Photo)

Devotees throw flower petals on an idol of the Hindu god Ganesh, the deity of prosperity, on the occasion of his birthday, celebrated as Magha Ganesh Jayanti, before immersing the idol into the Arabian sea, in Mumbai, India on February 16, 2021. (Photo by Francis Mascarenhas/Reuters)

Metropolitan Police patrol as people party at the Soho district, as the coronavirus disease (COVID-19) restrictions ease, in London, United Kingdom on April 16, 2021. Pubs and Restaurants are expecting good business tonight being the first Friday night after Coronavirus lockdown rules were relaxed to allow outside dining and drinking. (Photo by Henry Nicholls/Reuters)

Miss USA R'Bonney Gabriel, back to camera, is hugged by other contestants after being crowned Miss Universe at the 71st Miss Universe pageant, in New Orleans on Saturday, January 14, 2023. (Photo by Gerald Herbert/AP Photo)