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.

Anja Rubik poses as she arrives for the screening of the film “Dolor Y Gloria (Pain and Glory)” at the 72nd edition of the Cannes Film Festival in Cannes, southern France, on May 17, 2019. (Photo by Stephane Mahe/Reuters)

Model Bella Hadid poses for photographers at the photo call for the film “Pain and Glory” at the 72nd international film festival, Cannes, southern France, Friday, May 17, 2019. (Photo by Arthur Mola/Invision/AP Photo)

Starting on Monday, August 12, Perseid meteors will streak across the summer sky for a couple of nights, offering casual stargazers and serious nighttime photographers a chance to capture a glimpse of the annual meteor shower. Photo: Photographer David Kingham created this composite image from 23 photos on August 12, 2012. (Photo by David Kingham)

Bud Light Hotel Correspondent Leila Mahadin (R) interviews a Playboy Bunny at the 2012 Playboy Party hosted by Bud Light Hotel at Bud Light Hotel on February 3, 2012 in Indianapolis, Indiana. (Photo by Stephen Lovekin/Getty Images for Bud Light Hotel)

Illuminated Cut Paper Light Boxes by Hari & DeeptiDeepti Nair and Harikrishnan Panicker (known collectively as Hari & Deepti) are an artist couple who create paper cut light boxes. Each diorama is made from layers of cut watercolor paper placed inside a shadow box and is lit from behind with flexible LED light strips. The small visual narratives depicted in each work often play off aspects of light including stars, flames, fireflies, and planets.

People look at a Christmas tree decorated with colourful lights at a residential compound in Beijing on December 8, 2017. (Photo by Nicolas Asfouri/AFP Photo)