Overlooking qingshuitan Wetland Park in the air, thousands of Chinese fir trees turn green. Gaoyou City, Jiangsu Province, China, April 20, 2020. April 22 is world earth day. (Photo credit should read Costfoto/Barcroft Media via Getty Images)

A group of riders splash down a water slide in Bromont, Que on Monday, June 29, 2020 as water parks reopen in the province of Quebec, Canada. (Photo by Canadian Press/Rex Features/Shutterstock)

Wearing a protective mask to curb the spread of the new coronavirus a man attends a memorial for those who have died from COVID-19 worldwide, at Rio's Christ the Redeemer statue in Rio de Janeiro, Brazil, Wednesday, July 1, 2020. (Photo by Leo Correa/AP Photo)

An unidentified fashion lover waits outside Chanel's Haute Couture fashion show during snowfall in Paris, Tuesday January 22, 2019. (Photo by Thibault Camus/AP Photo)

A demonstrator wears a feather headdress during the “No on APEC” protest on the sidelines of the Asia-Pacific Economic Cooperation (APEC) Leaders' Meeting in San Francisco, California, on November 12, 2023. (Photo by Andrew Caballero-Reynolds/AFP Photo)

This tiny hedgehog is in a prickly position as hes unable to grow spikes, leaving him needing round-the-clock care. The woodland critter was found with no spikes and has been taken in by a family hoping to nurse him back to health so he can be released into the wild. Named Mr Prickleless, the hedgehog was rescued by Dina Nixon and her daughter Jennifer, 25, after being taken into a rescue centre in December last year. It is not known what happened to his spikes, but Dina has vowed that if they ever do return he will be returned to the wild. But for now the hedgehog has taken shelter in a rabbit hutch in her garden. (Photo by Caters News Agency)

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.

Residents of the Brussels suburb of Molenbeek are searched by police before taking part in a memorial gathering to honour the victims of the recent deadly Paris attacks, in Brussels, Belgium, November 18, 2015. (Photo by Yves Herman/Reuters)