A performer dressed as a zombie performs inside a “Zombie Shinkansen” bullet train bound for Osaka from Tokyo, inspired by the South Korean movie “Train to Busan” ahead of the Halloween season, Japan, on October 19, 2024. (Photo by Kim Kyung-Hoon/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.

Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

A model presents a creation from the fashion label Kakopieros during Australian Fashion week in Sydney, Australia, May 20, 2016. (Photo by David Gray/Reuters)

People participate in a winter fishing event in Changchun, Jilin province, China, December 25, 2016. Picture taken December 25, 2016. (Photo by Reuters/Stringer)

These heartwarming images capture the pure happiness of young children playing with a buffalo in the sweltering Indonesian heat on July 28, 2018. The children are all sons of the farmers who work on the rice farms in the West Java region of Indonesia. Amateur photographer Tamlikho Tam, 46 from Depok in West Java Indonesia snapped up the joyful moment because it shows what a typical childhood should be like without technology. (Photo by Tamlikho Tam/South West News Service)