Actress Olga Kurylenko poses for a photograph at the British Academy of Film and Arts (BAFTA) awards ceremony at the Royal Opera House in London February 16, 2014. (Photo by Suzanne Plunkett/Reuters)

Spanish rider Maikel Melero performs a jump during the Malaga Freestyle motocross show at the Malagueta bullring in Malaga, southern Spain, August 1, 2015. (Photo by Jon Nazca/Reuters)

A man rides a horse through flames during the annual “Luminarias” celebration on the eve of Saint Anthony's day, Spain's patron saint of animals, in the village of San Bartolome de Pinares, northwest of Madrid, Spain, January 16, 2017. (Photo by Paul Hanna/Reuters)

DJ David Guetta (R) and rapper Nicki Minaj perform onstage during the 2017 Billboard Music Awards at T-Mobile Arena on May 21, 2017 in Las Vegas, Nevada. (Photo by Mario Anzuoni/Reuters)

Princess Charlene poses after the arrival of the Riviera Water Bike Challenge in support of the Princess Charlene of Monaco Foundation, in Nice, France, June 4, 2017. (Photo by Eric Gaillard/Reuters)

An eight-year-old St Bernard with the longest canine tongue in the world, measuring 18.58cm (7.31in) in length, as recorded by the Guinness World Records: Amazing Animals, in South Dakota, USA. (Photo by Kevin Scott Ramos/GWR/PA Wire)

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 reveller performs while attending the block party “Galo da Madrugada” during carnival festivities in Sao Paulo, Brazil on February 25, 2020. (Photo by Rahel Patrasso/Reuters)