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

Daniel J. Wabsey, a 58-year-old war veteran, sits outside his tent at Camp Hope in Las Cruces, New Mexico October 6, 2015. “I've been traveling for 35 or 38 years. Getting inside would take a while to get used to. I just want to be able to eat, sleep and be safe. We all get along and understand in Camp Hope. We've all been there. With common sense you can survive out here”, Wabsey said. Camp Hope describe themselves as an “alternative transitional living project for the homeless”. Around 50 people live at the camp. (Photo by Shannon Stapleton/Reuters)

In this November 30, 2017 photo, Douglas scoops up mud from the bottom of the polluted Guaire River, in search of gold and anything valuable he can sell, in Caracas, Venezuela. Some stretches of the river smell of sewer while others emit a toxic odor of fuel, a stench that stays in ones nose for hours after leaving the water. (Photo by Ariana Cubillos/AP Photo)

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)

“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)