Photographer Gregg Segal travelled the world to document children and the food they eat in a week. Partly inspired by the increasing problems of childhood obesity, he tracked traditional regional diets as yet unaffected by globalisation, and ironically, found that the healthiest diets were often eaten by the least well off. (Photo by Gregg Segal/The Guardian)

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)

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)

This strange coral-looking specimen is actually a mushroom. The photo, “Beautiful Destroyer”, was taken in the Panamanian tropical rainforest where the mushroom produces nitrogen, an element vital to soil health. (Photo by Sarah A. Batterman)

A resident looks at a wildfire in Vina del Mar, Chile, March 12, 2017. Forest fires are a regular feature of Chile's hot, arid summers, but a nearly decade-long drought combined with historically high temperatures have created tinder-like conditions in the nation's central regions. (Photo by Rodrigo Garrido/Reuters)

Heads of love dolls are seen on the shelf on March 9, 2017 in Tokyo, Japan. Japan's oldest and largest “love doll” maker Orient Industry, has been producing silicone love dolls since 1977, and has seen there is a trend for intimate relationships with silicone dolls in Japan. (Photo by Taro Karibe/Getty Images)

A model prepares backstage during the body painting show : Miracle World The Ocean organized by Unipa Surabaya at Grand Atrium Royal Plaza on June 21, 2021 in Surabaya, Indonesia. (Photo by Robertus Pudyanto/Getty Images)