Police officers arrest a protester during an anti-lockdown march in Liverpool, United Kingdom on November 21, 2020. The StandUpX movement organised a protest under the banner March for Freedom, Save Our City. (Photo by Mercury Press)

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 22-year-old woman in a wedding gown is grabbed by Guo Zhongfan, a local community officer, as she attempts to kill herself by jumping out of a seven-storey residential building in Changchun, Jilin province. According to local media, the woman tried to commit suicide after her boyfriend of four years broke up with her, just as they were making plans to get married. The woman did not sustain any injuries during the incident. (Photo by China Daily/Reuters)

A lion statue that sits outside the New York Public Library building wears a mask in the Manhattan borough of New York City, New York, U.S., September 28, 2020. (Photo by Carlo Allegri/Reuters)

In this Tuesday, June 23, 2015, photo, an Israeli vendor waits for clients at the southern Israeli town of Sderot, next to the Israel-Gaza border. A year after the Gaza war, the community in southern Israel, long battered by rockets from the Hamas-run territory next door, has slowly recovered and is even seeing a quiet boom. (Photo by Oded Balilty/AP Photo)

UK's Love Island favourite Maura Higgins, 29, was seen wearing a short satin dress as she left Amazonico Restaurant in Mayfair, central London on October 28, 2020. (Photo by Splash News and Pictures)

Taylor Swift performs “All Too Well” at the 56th annual Grammy Awards at Staples Center. (Photo by Matt Sayles/Invision)

A relative performs rituals for a man who died of coronavirus disease (COVID-19), before his cremation at a crematorium in New Delhi, India, November 19, 2020. (Photo by Danish Siddiqui/Reuters)