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

“Sky burial or ritual dissection was once a common funerary practice in Tibet wherein a human corpse is cut in specific locations and placed on a mountaintop, exposing it to the elements or the mahabhuta and animals – especially to birds of prey. The location of the sky burial preparation and place of execution are understood in the Vajrayana traditions as charnel grounds. In Tibet the practice is known as jhator, which literally means, «giving alms to the birds»”. – Wikipedia

Photo: A burial master chops bones of a body to feed vultures during a celestial burial ceremony on April 19, 2006 in Dari County of Guoluo Prefecture, Qinghai Province, northwest China. Celestial burial is a traditional funeral of Tibetan people, which began in the 7th century. (Photo by China Photos/Getty Images)

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

Actor George Clooney is arrested with his father Nick Clooney (2R) during a demonstration outside the Embassy of Sudan March 16, 2012 in Washington, DC. United to End Genocide, the Enough Campaign and Amnesty International held a rally to call on the United States and world leaders to stop the violence in South Sudan and prevent hundreds of thousands of people from starving. (Photo by Win McNamee/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.

Mosha, the elephant that was injured by a landmine, has her prosthetic leg attached at the Friends of the Asian Elephant Foundation in Lampang, Thailand, June 29, 2016. Mosha was 7 months old when she stepped on a land mine near Thailand’s border with Myanmar and lost a front leg. That was a decade ago... (Photo by Athit Perawongmetha/Reuters)

West Berliners crowd in front of the Berlin Wall as they watch East German border guards demolish a section of the wall on November 11, 1989. (Photo by Gerard Malie/AFP Photo)

Iraqi troops fire artillery towards Islamic State (IS) group jihadists' positions in west Mosul on March 11, 2017 during the ongoing battle to retake the city from the group. (Photo by Aris Messinis/AFP Photo)