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 young arab boy, armed with a rifle and a knife, in the Aden Protectorate near Yemen. (Photo by Richards/Fox Photos/Getty Images). February 1938

Young Ian Archibald ponders the consequences of a complex critical study of beauty contestants during the Miss TV Times finals in London. (Photo by Central Press/Getty Images). 30 July 1971

Iran's Hanieh Rajabi performs during the women's Daoshu competition at the 13th Wushu World Championships in Jakarta, Indonesia, Monday, November 16, 2015. (Photo by Tatan Syuflana/AP Photo)

A Brazilian Navy member ejects spent cartridges while shooting rubber bullets during an exhibition of their operational capacity to combat terrorist attacks and riots ahead of the FIFA Confederations Cup and World Youth Day in Rio de Janeiro on May 27, 2013. (Photo by Ricardo Moraes/Reuters)

The northeastern United States sweltered this week in a scorching summer heat wave, complete with stagnant, sticky air and no winds for relief, forecasters said. Even in a summer already filled with stretches of very hot weather, this week will be stubbornly brutal, with no relief in sight until the weekend brings thunderstorms to the region, they said. "Plain and simple, this week may feel the worst of any week for this summer in the Northeast," said Accuweather.com meteorologist Alex Sosnowski. (Reuters)

English model Katie Price pictured going topless while on holiday with boyfriend Kris Boyson at Ammatara Pura Pool Villas resort in Thailand on July 13, 2018. The happy couple looked relaxed in matching yellow Bikini and shorts as they frolicked with each other by the pool as they enjoyed their first holiday together at exclusive resort in Thailand. (Photo by Backgrid UK)

“Lombard Street is an east-west street in San Francisco, California. Lombard Street is best known for the one-way section on Russian Hill between Hyde and Leavenworth Streets, in which the roadway has eight sharp turns (or switchbacks) that have earned the street the distinction of being the crookedest street in the world”. – Wikipedia

Photo: A single car drives down a typically crowded Lombard Street, San Francisco's crooked street, April 29, 2003 in San Francisco. (Photo by Justin Sullivan/Getty Images)