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 Hawker Hurricane Mk XIIa 5711 (G-HURI) fighter aircraft prepares to perform an aerobatic display at the IWM Duxford on October 18, 2012 in Duxford, England. The aeroplane, similar to those that defended British shores during the Battle of Britain in World War II, is due to be auctioned by Bonhams in their sale of “Collectors' Motor Cars and Automobilia” at Mercedes-Benz World Brooklands on December 3, 2012. The plane was built in 1942 and joined the Royal Canadian Air Force the following year, where it remained for the duration of the war, it is expected to fetch up to 17 million GBP. (Photo by Oli Scarff)

Pooh, a one-year-old cat, who lost his hind legs in an accident and has been given bionic paws, walks in a vet clinic in Sofia on January 31, 2017. Pooh, who is thought to have lost his legs in a car or train accident last April, is back on the prowl thanks to Bulgarian veterinary surgeon Vladislav Zlatinov. He is the first vet in Europe to successfully apply the pioneering method of Irish neuro-orthopaedic surgeon Noel Fitzpatrick, who shot to fame in 2009 when making Oscar the first bionic cat by fitting him with new hind legs in Britain. (Photo by Nikolay Doychinov/AFP Photo)

The expertly colourised shots were brought to life by French bank technician, Frédéric Duriez (51). The images were provided by the Valois collection which belongs to the BDIC. “By colourising these photos, I reduce the time that separates us today from this conflict”, said Frédéric. Here: Car cannon sections in firing position, Auxi-le-Château. (Photo by Frédéric Duriez/BDIC/Mediadrumworld.com)

Spanish flamenco dancer Salome Ramirez performs in the show “Authentic Flamenco”, the show of the Teatro Real in Madrid, at the Sao Pedro theater in Sao Paulo, Brazil, 14 December 2022. After a successful tour in the United States and India, the show has arrived in the country of samba and carnivals, this time by the dancer Eduardo Guerrero and his work “Faro”. (Photo by Isaac Fontana/EPA/EFE/Rex Features/Shutterstock)

A cow carrying a bell and autumn flowers headgear walks by in front of spectators at the traditional cattle show in Schwellbrunn, Switzerland, 26 September 2022. The traditional show in the Appenzell region is held annually in autumn, when local farmers return from the alp with their groomed and cleaned cows to present them on a show ground. “The most beautiful and best performing cows are awarded prizes”, the Appenzellerland tourism office adds on their website. (Photo by Gian Ehrenzeller/EPA/EFE)

Dublin Horse Show mascot “Conor the Capall” among the crowds on the opening day of the 147th Dublin Horse Show at the RDS on Wednesday, August 17, 2022, the first to be held since 2019. The event which was first held in 1864 takes place over the next five days and includes national and international show jumping competitions. (Photo by Brian Lawless/PA Images via Getty Images)

Photo taken on January 3, 2018 shows the snow-light show at the Sun Island International Snow Sculpture Art Expo in Harbin, capital of northeast China's Heilongjiang Province. Snow Wonderland, a 3D snow-light show applying modern sound, light and digital technologies has been displayed at Sun Island International Snow Sculpture Art Expo recent days. (Photo by Wang Jianwei/Xinhua via Getty Images)