A Chinese man wears a mask to protect against pollution as he waits at a red light while commuting to work in heavy smog on December 8, 2015 in Beijing, China. The Beijing government issued a 'red alert' for the first time since new standards were introduced earlier this year as the city and many parts of northern China were shrouded in heavy pollution. Levels of PM 2.5, considered the most hazardous, crossed 400 units in Beijing, lower than last week, but still nearly 20 times the acceptable standard set by the World Health Organization. The governments of more than 190 countries are meeting in Paris to set targets on reducing carbon emissions in an attempt to forge a new global agreement on climate change. (Photo by Kevin Frayer/Getty Images)

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.

Residents watch the ocean waves crash into the water front, after the passage of Hurricane Irma, in Cuba, Sunday, September 10, 2017. (Photo by Ramon Espinosa/AP Photo)

“Benny Hill (21 January 1924 – 20 April 1992) was a mainstream English comedian and actor, notable for his long-running television programme «The Benny Hill Show»”. – Wikipedia

Photo: British comedian Alfred Hawthorn Hill poses with a group of showgirls. (Photo by Wattie/Express/Getty Images). 17th January 1955

Edward, Prince of Wales (1840–1910), later King Edward VII, stands over the carcass of a wild Chillingham bull, shot by himself during a visit to Chillingham Castle, Northumberland, circa 1879. (Photo by Hulton Archive/Getty Images)

A new type of tandem at Alexandra Palace, London. (Photo by Fox Photos/Getty Images). June 1936

Naturally, it is important that a baby learn the right habits. This woman demonstrates that smoking is wrong for babies. From a series of images parodying women's lifestyle and beauty magazines. (Photo by Jacobsen/Getty Images). 1955

An activist of the anti-G8 forum “Block G8” shows his middle finger to a police helicopter passing overhead June 07, 2007 at Bollhagen, near Heiligendamm, Germany. (Photo by Carsten Koall/Getty Images)