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.

A portrait of French WWI soldier Edouard Marius Ivaldi is displayed on a tablet, in this illustration picture, alongside his battlefield grave memorial, a wooden cross with a battlefield helmet in Champagne, eastern France, November 3, 2015. (Photo by Charles Platiau/Reuters)

An injured NATO soldier lies on the ground following a suicide car bomb attack that targeted foreign military vehicles in the Afghan capital Kabul on June 30,2015. A powerful blast hit downtown Kabul on June 30 as a suicide car bomber targeted foreign military vehicles, officials said, with casualties feared. The blast came on the main road to the airport, around 500 meters (550 yards) from the US embassy and near a base for foreign troops.“It was a suicide car bomber targeting a convoy of foreign forces in Kabul”, interior ministry spokesman Sediq Sediq said. (Photo by Wakil Kohsar/AFP Photo)

Members of Wonderfam CausePlay pose for a group photo at Buttercup Sand Dunes on January 15, 2022 in Winterhaven, California. Buttercup San Dunes was the location of several iconic scenes filmed for Star Wars: Return of the Jedi. (Photo by Daniel Knighton/Getty Images)

A woman daubed in colours shakes her head to remove the coloured powder during Holi celebrations in Ahmedabad, India on March 18, 2022. (Photo by Amit Dave/Reuters)

Ukraine's Maryna Bekh-Romanchuk reacts during the women's triple jump final at the World Athletics Indoor Championships in Belgrade, Serbia on March 20, 2022. (Photo by Bernadett Szabo/Reuters)

A model presents a creation from the collection by Amato Couture, of the United Arab Emirates, during the Arab Fashion Week in Gulf emirate of Dubai, United Arab Emirates, 28 March 2022. (Photo by Ali Haider/EPA/EFE)

Racegoers pose for a photo during the Coral Scottish Grand National Ladies Day at Ayr Racecourse, Ayr, United Kingdom on Friday, April 1, 2022. (Photo by Steve Welsh/PA Images via Getty Images)