An archer in a samurai warrior costume aims at a target in the Asakusa Yabusame horseback archery event at Sumida Park in Tokyo, Saturday, April 18, 2015. (Photo by Shizuo Kambayashi/AP 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.

Pablo Holcer tests out a VR system made by Neurable that allows the user to control with their thoughts as the EEG headset interprets thoughts into actions in the VR environment at SIGGRAPH 2017 in Los Angeles, California, July 31, 2017. (Photo by Mike Blake/Reuters)

North Korean leader Kim Jong Un (3rd R) and wife Ri Sol Ju (4th L) enjoy an art performance given by the Chongbong Band to mark the 70th anniversary of the founding of the Workers' Party of Korea (WPK) in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 19, 2015. (Photo by Reuters/KCNA)

Relatives and friends react during the funeral of Bryan Sandoval, 17, a victim of a landslide that has left at least 112 dead and 350 missing people, in El Cambray II village, Santa Catarina Pinula, Guatemala, 04 October 2015. The landslide took place on 01 October 2015 when heavy rains saturated the soil. (Photo by Esteban Biba/EPA)

A picture taken with a drones shows Kayakers make use of the current that flows over a dike in the flood plains of the Waal river, with the Waal bridge of Nijmegen in the background in Lent, the Netherlands, 04 February 2021. The heavy rainfall and snow melt in southern Germany has caused a significant rise in the water level in various places in the Netherlands. (Photo by Robin Van Lonkhuijsen/EPA/EFE)

A history enthusiast, dressed as a soldier, fights during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna December 5, 2015. Hundreds of history enthusiasts gathered near the city of Slavkov before a re-enactment of Napoleon's famous battle of Austerlitz on Saturday to mark its 210th anniversary. (Photo by David W. Cerny/Reuters)

Paragliders fly towards the landing area of the “Acro Show” above Lake Geneva in Villeneuve, Switzerland on Sunday, August 26, 2018. (Photo by Valentin Flauraud/Keystone via AP Photo)