Milena Pino, 15, puts on makeup prior to taking part in a speed competition with horses at the International Livestock Fair Show in Havana March 21, 2015. (Photo by Alexandre Meneghini/Reuters)

Jared Leto poses with fans for a selfie during the “Clear Channel Media and Entertainment” at the 2014 Cannes Lions on June 18, 2014 in Cannes, France. (Photo by Didier Baverel/WireImage)

Students celebrate their A-level results at King Edward VI High School for Girls in Birmingham, England on August 18, 2016. The proportion of top grades achieved by A-level students across the UK has fallen for a fifth year in a row, and girls have caught up with boys in attaining A* grades. (Photo by Joe Giddens/PA Wire)

People participate in a winter fishing event in Changchun, Jilin province, China, December 25, 2016. Picture taken December 25, 2016. (Photo by Reuters/Stringer)

Several beaches along South Florida's Atlantic coast line were closed after thousands of sharks were seen migrating in the waters. The sharks were migrating from Boca Raton to Jupiter since the beginning of March, marine biologists told NBC Miami. Photo: A spinner shark swims just offshore on Midtown Beach in Palm Beach on Tuesday. (Photo by Jeffrey Langlois/Palm Beach Daily News)

Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

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.

Toyoda Gosei Co Ltd's personal mobility concept airbag car "Flesby" is displayed at the 44th Tokyo Motor Show in Tokyo, Japan, October 28, 2015. (Photo by Yuya Shino/Reuters)