A girl reacts during a rehearsal for the Independence Day military parade in central Kiev, Ukraine, August 19, 2016. (Photo by Valentyn Ogirenko/Reuters)

Soldiers march during a military parade commemorating the 37th anniversary of the founding of the Nicaragua's army, in Managua, Nicaragua September 3, 2016. (Photo by Oswaldo Rivas/Reuters)

Children with balloons play beside the statue of British comedy legend Eric Morecambe on January 16, 2012 in Morecambe, England. According to scientists January 16, 2012 was “Blue Monday”, the most depressing day of the year. (Photo by Christopher Furlong/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.

In this Monday, March 16, 2015 photo, Syrian refugee Samira Helal, 17, who is two months pregnant, poses for a portrait at inside her tent at an informal tented settlement near the Syrian border, on the outskirts of Mafraq, Jordan. Nearly 3.8 million Syrians have fled their country and are now registered as refugees, according to the U.N. Most face increasingly desperate circumstances. (Photo by Muhammed Muheisen/AP Photo)

Supporters of Filipino boxer and Senatorial candidate Manny Pacquiao, wait for election souvenirs thrown by Pacquiao during election campaigning in Malabon Metro Manila in the Philippines May 6, 2016. Boxing star Manny Pacquiao pressed on with his campaign for a seat in the Philippine Senate despite a reported militant plot to kidnap him. (Photo by Erik De Castro/Reuters)

“The knight and his steed”. This picture was taken in a natural but controlled environment. There are pictures that can not be done in nature or that would imply a very high cost of both time and money, thats why photography workshops are run conducted at strategic locations and bringing EVERYONE who is interested, the basic notions (lighting, camera handling, composition, etc...) or the specimens, and afford them the opportunity to take pictures like this. Although controlled, this shot was not prepared at all, I was performing a workshop with the agalychnis callidryas treefrog from Costa Rica when the frog managed to jump to the branch where this huge titan was sleeping... I had my gear ready so I only had to change a few settings and shoot... the rest is history. (Photo and caption by Nicolas Reusens Boden (Sweden)/2014 Sony World Photography Awards)

British artist Nick Veasey used an X-ray machine to show us exactly what's going on under people's clothes. The equipment took copies of items separately before they were mashed together to create characters and situations. The work is part of Veasey's latest exhibition named “X-ray Voyeurism”. In order to create the work, the 51-year-old has spent the last 20 years exposing himself to harmful radiation in his studio. Photo: “Stripper”: Has tucked her cash away safely. (Photo by Nick Veasey/Barcroft Media)