A green rosella and a wallaby, known as a Pademelon, eye off as they drink from a water bowl put out for thirsty wild animals at a back-yard in Kayena, in northern Tasmania, 01 February 2019. Australia recorded its hottest month on record in January; it was also the hottest and driest month on record for the Australian island state of Tasmania. (Photo by Barbara Walton/EPA/EFE)

Marieke van der Meer from the Netherlands works on her sculpture “Flora” at the sand sculpture show in Binz on Ruegen island, Germany, 09 March 2016. With the motto “Fascination Nature”, 50 sand artists have created oversized sculptures. The sculptors use 16,000 tons of special sand that is pressed into big blocks first and then formed. The 7th sand sculpture show on 5,600 square meters of exhibition ground opens on 12 March 2016. (Photo by Ens Buettner/EPA)

In this handout photo provided by the Helmholtz Center for Research on Infectious Diseases an EHEC bacteria is visible on May 30, 2011 in Berlin, Germany. German health authorities have attributed at least 14 deaths within the last two weeks to an outbreak of enterohemorrhagic E. coli, also known as the EHEC bacteria. (Photo Courtesay Manfred Rohde, Helmholtz-Zentrum fuer Infektionsforschung (HZI)/Getty Images)

English singer and songwriter Dua Lipa performs onstage during the Dua Lipa Future Nostalgia Tour at FTX Arena on February 09, 2022 in Miami, Florida. (Photo by Jason Koerner/Getty Images)

A Ukrainian soldier smiles in front of a city sign reading ''I Love Izium'' in Izium, Kharkiv region, Ukraine, Tuesday, September 14, 2022. Ukrainian troops piled pressure on retreating Russian forces pressing deeper into occupied territory and sending more Kremlin troops fleeing ahead of the counteroffensive that has inflicted a stunning blow on Moscow's military prestige. (Photo by Kostiantyn Liberov/AP Photo)

A woman takes a selfie picture as Turkish Kurds gather as part of Newroz celebrations in Diyarbakir, on March 21, 2016. Nowruz, the Farsi-language word for “New Year”, is an ancient Persian festival, celebrated on the first day of spring, on March 21, in Central Asian republics, Iraq, Turkey, Afghanistan and Iran. (Photo by Ilyas Akengin/AFP Photo)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via 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.