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.

Participants, one of them loosing balance, jump in a sack race at a shopping center in Paris to win a 500 euros voucher (537 USD), on the first day of the winter sales in Paris, France, Wednesday, January 6 , 2016. The five-week 2016 winter sales start everywhere across France on Wednesday Jan. 6 and end on Feb. 16. (Photo by Francois Mori/AP Photo)

Factory landlord Lawrence Taylor (L), portraying a Colour Sergeant from the King's Royal Rifle Corps, part of the Rifles Living History Society, performs a drill with Connor Young (R) of the Queen's Own Royal West Kent Regiment Living History Group as they recreate the life of a First World War soldier at the Eden Valley Museum in Edenbridge in southeast England May 10, 2014. Lawrence has always had an interest in military history and specifically “The Rifles” – his veteran father's WWII regiment. When he became a re-enactor he chose not to re-enact WWII as many of the veterans are still alive, and he felt uncomfortable as he remembers his father would have flashbacks and nightmares about the war. United by a fascination with military history and a fondness for dressing up, groups such as the Rifles Living History Society and the Queen's Own Royal West Kent Regiment Living History Group get together to recreate aspects of life during the First World War. Reuters photographer Luke MacGregor photographed members of the groups, both as they took part in living history events and at their day jobs. (Photo by Luke MacGregor/Reuters)

A Black Pete interacts with children during the arrival of Sinterklaas, or Saint Nicholas, in Maassluis, Netherlands, Saturday, November 12, 2016. Sinterklaas and his helper Black Pete are at the center of a long-time controversy because Pete is often played by white people in blackface makeup. (Photo by Peter Dejong/AP Photo)

A large teddy bear, used to enforce social distancing, is pictured sitting at a cafe in Pristina on July 23, 2020, as Kosovo authorities announce new measures to fight against the resurgence of the COVID-19, the novel coronavirus. (Photo by Armend Nimani/AFP Photo)

Men dressed as Elvis Presley carry a volunteer during a street parade at the 25th annual Parkes Elvis Festival in the rural Australian town of Parkes, west of Sydney, January 14, 2017. (Photo by Jason Reed/Reuters)

Model Kendall Jenner attends the “120 Battements Par Minutes (120 Beats Per Minute)” screening during the 70th annual Cannes Film Festival at Palais des Festivals on May 20, 2017 in Cannes, France. (Photo by Eric Gaillard/Reuters)

A businessman walks past an empty baby Tyrannosaurus rex costume near Faneuil Hall in Boston, Thursday, May 17, 2018. An actor left the costume on the sidewalk as he went to retrieve his parked car, after entertaining midday tourists. (Photo by Charles Krupa/AP Photo)