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.

People walk down the street while Hurricane Matthew approaches in Port-au-Prince, Haiti October 3, 2016. (Photo by Carlos Garcia Rawlins/Reuters)

The festival marks the end of the monsoon season and beginning of autumn. More than hundred girls under the age of nine gathered for the tradition of worshiping young pre-pubescent girls as manifestations of the divine female energy. The ritual holds a strong religious significance in Newar community. It is a community affair held primarily to save small girls from diseases and bad luck in the years to come. Photo: A young Nepalese girl dressed as a Kumari or living Goddess, smiles for camera as she waits for Kumari puja at Hanuman Dhoka, Basantapur Durbar Square in Katmandu, Nepal, Tuesday, September 17, 2013. (Photo by Niranjan Shrestha/AP Photo)

A Thai visitor appears to be frightened by a life-size Velociraptor model also known as Raptor at the Dinosaur Planet theme park in Bangkok, Thailand, 25 March 2016. The 500 million baht (14 million US dollars or 12 million euro) theme park opening in the Thai capital aimed to attract more than 15,000 visitors a day featuring a chance to experience more than 200 dinosaurs from various species that are brought back to life. (Photo by Rungroj Yongrit/EPA)

A woman with a snake on her body, taken in Rio de Janeiro, Brazil, April 2017. A holistic therapist uses snakes to massage her clients – claiming it cures depression and even helps victims of abuse. Instead of traditional massaging techniques, Sarah Zaad uses up to six pythons and boa constrictors on brave customers who want to relax or be treated for mental disorders. The flamboyant therapist from Rio de Janeiro, Brazil believes her snakes have a magic touch, which can benefit people by massaging their bodies. (Photo by Kadeh Ferreira/Barcroft Images)

A truck driver naps under his truck at the fancy bazaar area during the twelve hours Assam bandh or strike in Guwahati, Assam, India, 23 October 2018. At least 46 organisations are observing a 12-hour bandh across the state to protest against the Centre's bid to clear the Citizenship (Amendment) Bill 2016, in the Winter Session of Parliament. (Photo by EPA/EFE/Stringer)

A young performer cries as she parades during the Bun Festival on Cheung Chau island in Hong Kong Tuesday, May 6, 2014. Bun Festival, the Taoist God of the Sea, is worshipped and evil spirits are believed to be scared away by loud gongs and drums during the procession. The celebration includes bun scrambling, parades, opera performances, and children dressed in colorful costumes. (Photo by Kin Cheung/AP Photo)

Bottles of vintage cognac, with a royal warrant stamp, are seen in storage inside Berry Bros and Rudd wine merchants in central London, Britain, August 21, 2015. Berry Bros. & Rudd, which started as grocers over 300 years ago in St. James's, central London, has two royal warrants. Every year Queen Elizabeth grants about 20 royal warrants, the gold emblem of the British monarchy, in a practice dating back to medieval times. The warrant holders can display the certificate and use the royal coat of arms in their marketing. The warrants lasting five years can help businesses break into new markets overseas, using their role as supplier to the royal family as a gauge of quality. On September 9, Queen Elizabeth will overtake Queen Victoria as Britain's longest-serving monarch. (Photo by Toby Melville/Reuters)