A little girl hangs three Siamese kittens on a washing line in a garden in Croydon, London. (Photo by Fox Photos/Getty Images). 14th July 1931

“The Family of Man” opened at The Museum of Modern Art in January 1955 and was curated by Edward Steichen. It was groundbreaking in its scope – 503 images by 273 photographers from 68 countries – as well as in the numbers of people who experienced it on its tour through 88 venues in 37 countries. The touring exhibit drew over 9 million people and the accompanying catalog sold over 2.5 million copies. Here: “Coney Island, New York”, by American photographer Garry Winogrand, circa 1952. (Photo by Garry Winogrand)

The sun rises behind The Royal Liver Building in Liverpool, Merseyside on Tuesday, January 17, 2023. (Photo by Peter Byrne/PA Images via Getty Images)

Russian Tu-95MS strategic bombers fly in formation during rehearsals for the Victory Day military parade, with St. Basil's Cathedral seen in the foreground, in central Moscow May 5, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Tatyana Makeyeva/Reuters)

A farmer uses a GoPro as he takes a picture of his carabao kneeling during the annual Carabao Festival in Pulilan, Bulacan in northern Philippines May 14, 2015. Water buffalos, locally known as carabaos, are led during a parade in the streets of the town to honour its patron saint San isidro Labrador, and carabaos will kneel in front of the church to give thanks for a year-long bountiful harvest. (Photo by Lorgina Minguito/Reuters)

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 blurred panaroma of Roemerberg historic center is reflected in a soap bubble in Frankfurt am Main, Germany, 09 July 2015. (Photo by Frank Rumpenhorst/EPA)

An injured protestor is led away during clashes with police near Tahrir Square on November 23, 2011 in Cairo, Egypt. Thousands of Egyptians are continuing to occupy Tahrir Square after four days of clashes with security forces despite a promise from military leaders to bring forward Presidential elections. (Photo by Peter Macdiarmid/Getty Images)