Young men play basketball on an improvised court wedged between a construction site and the shells of once grand colonial homes in Havana, July 20, 2015. As much as the young in Cuba welcome political opening and economic reform, such changes are unlikely to filter down to their lives anytime soon. (Photo by Meridith Kohut/The New York Times)

Jennifer Lopez Gets Loud for Hillary Clinton at Get Out The Vote concert on October 29, 2016 in Miami, Florida. (Photo by Larry Marano/Rex Features/Shutterstock)

Indian School children's in a traditational attire of a characters of Indian epic Ramayan, on the eve of children's day celebration at cubbon park, in Bangalore, India, 13 November 2016. Children's day (also known as Bal Divas), in India is celebrated every year on 14th of November to increase the awareness of people towards the rights, care, and education of children. Many schools hold activities and allow students to have fun and attend their classes in coloured dresses. (Photo by Jagadeesh N.V./EPA)

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.

Soldiers pose for a photo during the flower exhibition marking the 105th birth anniversary of the country's founding father, Kim Il Sung in Pyongyang, North Korea April 16, 2017. (Photo by Damir Sagolj/Reuters)

Tourists walk as others relax on the beach in the Red Sea resort of Hurghada, Egypt, July 17, 2017. (Photo by Gleb Garanich/Reuters)

A woman gets a pedicure in Port-au-Prince, Haiti, on October 13, 2017. (Photo by Andres Martinez Casares/AP Photo)

These images show the unique bond a group of free divers formed with gigantic sperm whales. Swimming just inches away from the huge mammals, the divers are dwarfed in size, made to look like specks in comparison. The photos were taken by renowned underwater photographers Alexandre Roubaud and Alexandre Voyer, who are based in Paris but travel the world to capture such stunning imagery. Here: a diver with a sperm whales. (Photo by Alexandre Roubaud/Alexandre Voyer/Caters News)