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.

Playboy Bunnies pose for a selfie at the premiere of “The Transporter Refueled” at Playboy Mansion in Los Angeles, California August 25, 2015. The movie opens in the U.S. on September 4. (Photo by Mario Anzuoni/Reuters)

Rowers enter in Canaregio river during the 42nd Venice Vogalonga on May 15, 2016 in Venice, Italy. 42 years ago a group of Venetians, both amateur and professional rowers, came up with an idea of non-competitive race in which any kind of rowing boat can take part. The first Vogalonga began with the message to protest against the growing use of powerboats in Venice and the swell damage they do to the historic city. (Photo by Awakening/Getty Images)

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)

Genko Stoykov fires a rifle as he and other men prepare for the traditional “Horo” dance on Epiphany Day in the icy winter waters of the Tundzha river on January 6, 2022 in Kalofer, Bulgaria. As part of the tradition, a priest throws a cross in the river and it is believed that the one who retrieves it will be healthy throughout the year. Today, cultures throughout Christendom mark the Feast of the Epiphany, when Jesus was revealed to the Magi as God incarnate. (Photo by Hristo Rusev/Getty Images)

A model presents a creation by LARHHA during the Code'41 Andalusian Fashion Week at the Amphitheatre of Italica in Seville on March 21, 2021. (Photo by Cristina Quicler/AFP Photo)

Local residents walk past tiger paintings, that marks the upcoming Lunar New Year of the tiger, in front of a department store in Taipei on January 27, 2022. (Photo by Sam Yeh/AFP Photo)

Ukrainians attend an open military training for civilians on a training range in Kiev, Ukraine, 30 January 2022. According to a survey conducted by the Kiev International Institute of Sociology (KIIS) from December 2021, 50.2 percent of Ukrainians said they would resist in case of a Russian military intervention into their city, town or village. Every third respondent to the poll said they were ready to engage in armed resistance, and 21.7 percent said they were ready to participate in civil resistance actions. (Photo by Sergey Dolzhenko/EPA/EFE)