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 shopkeeper shows golden accessories of Iphone at a shopping mall on March 25, 2011 in Qingdao, China. (Photo by ChinaFotoPress/Getty Images)

Lance Sergent Martin Mitchell (R) pins medals to Coldstream Guardsman Martin Hughes in the Tailor Shop in Wellington Barracks on April 20, 2011 in London, England. Soldiers involved in the Royal Wedding of Prince William and Catherine Middleton are preparing their ceremonial duties ahead of the day. (Photo by Oli Scarff/Getty Images)

Artist Princess Tarinan von Anhalt throws paint into the flow of air coming from the engine of Flexjet’s Learjet 40 XR engine to create a painting on a canvas at Signature Flight Support in West Palm Beach, Florida. The artist associated with the Jet Art Group used the help of Flexjet and their plane to spray paint on a canvas to create distinctive paintings to celebrate the 50th anniversary of Learjet. (Photo by Thomas Cordy/The Palm Beach Post)

“The Antonov An-124 Ruslan (NATO reporting name: Condor) is a strategic airlift jet aircraft. It was designed by the Soviet Union's Antonov design bureau. It is the world's largest ever serially-manufactured cargo airplane and world's second largest operating cargo aircraft. During development it was known as Izdeliye 400 in house, and An-40 in the West. First flown in 1982, civil certification was issued on 30 December 1992”. – Wikipedia

Photo: The new metro called “Bombardier MOVIA” with 22,50 meters long and 3,2 meters wide is load on a Antonow An-124 plane for transport to India on February 25, 2009 in Parchim, Germany. (Photo Handout Bombardier Transportation via Getty Images)

A tourist clad in Japanese kimono takes a picture in front of s portrait shop in Tokyo's Asakusa district, Thursday, February 15, 2018. Asakusa is a popular district four tourists in the capital. (Photo by Shizuo Kambayashi/AP Photo)

Rick Kelly, owner of Carmine Street Guitars, poses for a picture at his shop in New York City, U.S., July 21, 2016. Kelly builds custom guitars from the “bones of New York”, using reclaimed lumber from historic New York buildings. (Photo by Joe Penney/Reuters)