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 worker manually changes the direction of the bonde, the typical tram line in Santa Teresa neighborhood, using a rope in Rio de Janeiro, Brazil, September 9, 2015. The Santa Teresa bonde, called “Bondinho” in Portuguese, is running with passengers as a part of a test period, after the service was suspended in 2011 following an accident that killed six people, according to residents. (Photo by Pilar Olivares/Reuters)

These stunning light art pictures of skateboarding skeletons were created by Darren Pearson from Los Angeles. He works as a full time illustrator by day and by night he explores the varying landscapes of California in search of the perfect scene for his light-sculptures. Pearson makes complex light-effect photographs, none of which are photoshopped. He describes the work as location-based light art. Photo: A light skateboarder grinding a rail. (Photo by Darren Pearson/Caters News)

Hedi Xandt imagines impressive sculptures. Mixing styles and materials with talent, the artist invites us to discover his dark and intense universe.

These images of young children training were taken at a gymnastics summer camp in Bozhou, Anhui province, China on July 28, 2015. Children with promise are selected to attend, and their families hope training will not only benefit their children physically but also increase ‘willpower’, according to China News Service. (Photo by ChinaFotoPress/ChinaFotoPress via Getty Images)

A festival goer cools down with fresh water while taking part in the Hellfest metal music festival on June 17, 2022 in Clisson, western France. (Photo by Loic Venance/AFP Photo)

A reveller from Tom Maior Samba School takes part in a carnival at Anhembi Sambadrome in Sao Paulo February 14, 2015. (Photo by Nacho Doce/Reuters)

A young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)