A participant shows off a belt buckle during the 20th annual Seattle Invitationals, an amateur Elvis impersonator competition, in Seattle, Washington January 23, 2015. The event drew hundreds of spectators for 20 contestants at the Crocodile, a venue in Seattle's Belltown neighborhood. (Photo by David Ryder/Reuters)

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)

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.

“eLEGS is a wearable, artificially intelligent, bionic device that enables people with paralysis to stand up and walk again. The exoskeleton is battery-powered and rechargeable, fitting comfortably and securely over clothing. Initially, eLEGS will be used under medical supervision for rehabilitation and training”. – BerkeleyBionics.com

Photo: Paralysis victim Stephanie Sablan (L) is helped by physical therapist Shonna Moran as she walks using eLEGS robotic legs at Santa Clara Valley Medical Center on May 25, 2011 in San Jose, California. Sablan, 24, was paralyzed from the waist down earlier this year when she was in a car accident and has begun using the newly developed eLEGS made by Berkeley Bionics. The robot-like battery powered eLEGS fit over clothing and enables people with paralysis to stand up and walk again. (Photo by Justin Sullivan/Getty Images)

Revelers dressed as Santa Claus or in festive costumes arrive for the start of SantaCon 2018 in New York City December 8, 2018. SantaCon is an annual event where people dress as Santa Claus or other Christmas characters parade in several cities around the world. (Photo by Timothy A. Clary/AFP Photo)

In this April 4, 2014 file photo, a community policeman kicks a man who they alledge participated in an ambush against them near the town of La Concepcion, Mexico. The vigilante force was set-up by affected communities opposed to the construction of the La Parota hydroelectric dam. Two vigilantes were injured and one died. (Photo by Bernandino Hernandez/AP Photo)