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 Ukrainian woman begs Ukrainian President Petro Poroshenko to stop the bombing in Donetsk after shell hit the residential area where she lives, killing two civilians in Donetsk's Kyibishevsky district, on January 29, 2015. (Photo by Manu Brabo/AFP Photo)

A picture made available 27 November 2015 shows a handler putting his head between the gaping fangs of a crocodile during a show at the Samutprakarn Crocodile Farm and Zoo, Samutprakarn province, outside Bangkok, Thailand, 26 November 2015. The farm and zoo claims to be the world's largest crocodile farm with more than 80,000 freshwater and marine crocodiles, and offers shows such as crocodile wrestling to attract tourists. (Photo by Diego Azubel/EPA)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

Swedish brown bears “Fred” and “Frode” play in the snow on January 30, 2014 at the Natur- und Umweltpark (NUP) animal park in Guestrow, northeastern Germany. Despite of icy temperatures, the bear brothers took a break from their winter rest. (Photo by Bernd Wuestneck/AFP Photo/DPA)

Marine biologist Simon Pierce, who studies whale sharks, happened to be in the right place at the right time to capture amazing photo off Cancun, Mexico. (Photo by Simon Pierce/Mercury Press/Caters News)

More than 1,200 vintage posters that would send any movie buff into orbit were discovered in an Ohio garage, including the only known copy of an almost 7-foot-tall creation for the 1947 reissue of “Dracula” that could sell for $40,000. The Dallas-based Heritage Auctions in Dallas puts them all on the block March 22 and 23, including some rare specimens from the silent movie era. (Photo by Courtesy Heritage Auctions)

A waitress of The Palais de Tokyo restaurant wears a protective face mask as a precaution against the coronavirus in Paris, Saturday, September 5, 2020. New French cases of COVID-19 jumped in 24 hours to nearly 9,000, health officials said Friday. The 8,975 new cases were the highest number of infections since France successfully grappled with the spread of the coronavirus during a strict two-month lockdown. There were some 1,800 cases less a day earlier and more than for European neighbors. (Photo by Francois Mori/AP Photo)