Cosplay fans (R) take selfies as comic book and gaming fans attend the annual Ani-Com and Games Fair in Hong Kong on July 28, 2017. Tens of thousands were expected to attend the annual event on animation, comics and games, from July 28 to August 1. (Photo by Isaac Lawrence/AFP Photo)

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.

An Egyptian boy rides his donkey in front of a cafeteria with a picture of former Barcelona's forward player Lionel Messi at a village, near Giza, on the outskirts of Cairo, Egypt, February 7, 2022. (Photo by Amr Abdallah Dalsh/Reuters)

A Palestinian youth sets a beach umbrella on the shore off of Gaza City, on January 12, 2022. (Photo by Mohammed Abed/AFP Photo)

Costumed participants of a lacquer and leather ship, the so-called “Torture Ship”, kiss before putting out to Lake Constance for a pleasure cruise at the harbor of Friedrichshafen, Germany, 29 June 2019. Hundreds of leather and rubber fans set sail for the boat trip through the night on Lake Constance. (Photo by Daniel Kopatsch/EPA/EFE)

Japanese Yuuka Hasumi, 17, and Ibuki Ito, 17, also from Japan, who want to become K-pop stars, perform during their street performance in Hongdae area of Seoul, South Korea, March 21, 2019. (Photo by Kim Hong-Ji/Reuters)

A girl dives under a wave at Bondi Beach as temperatures reached 29 degrees celsius on December 17, 2020 in Sydney, Australia. The Bureau of Meteorology predicted the arrival of thunderstorms and showers later today with a southerly change bringing possible severe storms around the Sydney region. (Photo by Mark Evans/Getty Images)

Female Afghan National Police (ANP) officers aim their weapons during a drill at a training centre near the German Bundeswehr army camp Marmal in Mazar-e-Sharif, northern Afghanistan on December 11, 2012. (Photo by Fabrizio Bensch/Reuters/File Photo)