The original first mechatronic E.T. character from Steven Spielberg's 1982 film “E.T. the Extra Terrestrial” on display at Julien's Auctions in Beverly Hills, California on December 12, 2022, ahead of the “Julien's Auctions and TCM Present: Icons & Idols: Hollywood”. The auction will take place in-person and online on December 17 and 18. (Photo by Frederic J. Brown/AFP Photo)

Festival goers wear Australia day attire at Big Day Out 2012 at the Sydney Showground on January 26, 2012 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)

Vendors selling bread wait for customers at a roadside hotel in Quetta on March 25, 2024. (Photo by Banaras Khan/AFP Photo)

Confiscated rare and protected wildlife products such as these stuffed Sumatran tiger skins are burned and destroyed during a ceremony by government forestry and wildlife officials in Banda Aceh, Aceh province, Indonesia May 23, 2016 in this photo taken by Antara Foto. (Photo by Irwansyah Putra/Reuters/Antara Foto)

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 woman stands on the footbridge over the river Garry near Pitlochry, Scotland, Britain on October 10, 2018. (Photo by Russell Cheyne/Reuters)

A visitor takes a photograph from the North Star observation capsule onboard the cruise ship Quantum of the Seas which is currently docked at Southampton on October 31, 2014 in Southampton, England. Billed as the world's first smartship, Royal Caribbean's Quantum of the Seas is claimed to be the most high-tech cruise ship in the world, with high tech modifications such as virtual balconies in windowless rooms and features such as the first dodgem ride on water, and a skydiving simulator. The ship will shortly begin its voyage from Southampton, where it docked earlier this week, to New York before relocating to the Caribbean for the 2014-15 season. (Photo by Matt Cardy/Getty Images)

One of the two wooden rafts of the Kon-Tiki II expedition is prepared at the port of Callao prior to the departure to Pascua island in Chile, in Callao, Peru, October 30, 2015. Fourteen men from various parts of the world set out on rafts to commemorate the Norwegian navigator Thor Heyerdahl expedition 68 years ago. The original raft crossed the Pacific Ocean from South America to the Polynesian Islands. This rafts are a replica of ships used 6,000 years ago, but will be equipped with solar panel. (Photo by Mariana Bazo/Reuters)