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 prototype of the Space Exploration Technologies Corp. (SpaceX) Starship launch vehicle stands during an event at the SpaceX launch facility in Cameron County, Texas, U.S., on Saturday, September 28, 2019. Elon Musk gave space fans an update Saturday evening on the status of “Starship”, the next-generation vehicle his SpaceX plans to use to eventually take humans to Mars. (Photo by Callaghan O'Hare/Reuters)

Model Kendall Jenner presents a creation during the 2016 Victoria's Secret Fashion Show at the Grand Palais in Paris, France, November 30, 2016. The pulse-quickening, celebrity-filled catwalk event of the year: the Victoria's Secret fashion show takes place in Paris with performances from Lady Gaga and Bruno Mars. (Photo by Charles Platiau/Reuters)

Houses near Taal Volcano's crater are seen buried in volcanic ash from the volcano's eruption on January 14, 2020 in Taal Volcano Island, Batangas province, Philippines. The Philippine Institute of Volcanology and Seismology raised the alert level to four out of five, warning that a hazardous eruption could take place anytime, as authorities have evacuated tens of thousands of people from the area. An estimated $10 million worth of crops and livestock have been damaged by the on-going eruption, according to the country's agriculture department. (Photo by Ezra Acayan/Getty Images)

An employe of Russian Space Training Center hangs out to dry space suits of Russian cosmonaut Anatoly Ivanishin, NASA's U.S. flight engineer Kathleen Rubins, and Japanese space agency's flight engineer Takuya Onishi, right, after their undergoing training near in Noginsk, 60 km (38 miles) east of Moscow, Russia, Wednesday, July 2, 2014. The training was intended to simulate the capsule landing on water. Russian cosmonaut Anatoly Ivanishin, Japanese space agency's flight engineer Takuya Onishi, and NASA's U.S. flight engineer Kathleen Rubins are being trained for a future mission to the International Space Station. (Photo by Alexander Zemlianichenko/AP Photo)

A dhobi, or a washerman washes cloths on the banks of the River Gomti in Lucknow, India, Saturday, September 12, 2020. Dhobis are traditional laundry workers who wash clothes by hand and dry them in the sun, an occupation which has been in existence for generations. Most cities in India have a Dhobi Ghat, or washermen's area, where the city's pile of clothes is laundered. This practice is still popular in India, despite of modern technology. Around 1,000 families work in Lucknow's Dhobi Ghat. However, in light of the novel coronavirus, their wages have decreased drastically. With each family earning around US$100-200 per month. (Photo by Rajesh Kumar Singh/AP Photo)

People drink in the street in the Soho area of London, on April 12, 2021 as coronavirus restrictions are eased across the country in step two of the government's roadmap out of England's third national lockdown. Britons on Monday toasted a significant easing of coronavirus restrictions, with early morning pints – and much-needed haircuts – as the country took a tentative step towards the resumption of normal life. Businesses including non-essential retail, gyms, salons and outdoor hospitality were all able to open for the first time in months in the second step of the government's roadmap out of lockdown. (Photo by Tolga Akmen/AFP Photo)

Activists protest the Shell Oil Company's drilling rig Polar Pioneer which is parked at Terminal 5 at the Port of Seattle, Washington May 16, 2015. Hundreds of activists in kayaks and small boats fanned out on a Seattle bay on Saturday to protest plans by Royal Dutch Shell to resume oil exploration in the Arctic and keep two of its drilling rigs stored in the city's port. (Photo by Jason Redmond/Reuters)