A young man, who says he is part of a local criminal gang, poses for a picture holding a gun in the neighbourhood of Korogcho in Nairobi, Kenya, March 19, 2015. Around 2 million people live in the shantytowns packed in around Kenya's capital. Crime is high amid chronic unemployment levels, while basic services and sanitation are scarce. Residents try to make the best of things, eking out a living and picking up work where they can. (Photo by Siegfried Modola/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.

Sustainable development goal target 12.5 is to reduce waste. But with a planet increasingly dependent on technology, is that even possible? As of today, over 30m tonnes of electronic waste has been thrown out so far this year, according to the World Counts. Most e-waste is sent to landfills in Asia and Africa where it is recycled by hand, exposing the people who do it to environmental hazards. Kai Loeffelbein’s photographs of e-waste recycling in Guiyu, southern China show what happens to discarded computers. (Photo by Kai Loeffelbein/laif Agentur)

An older model Ford Mustang sits on cinder blocks with missing wheels near an abandoned apartment building in Detroit, Michigan January 7, 2015. Detroit, also known as the Motor City, is the historic hub of automobile manufacturing in the United States. A federal judge in December 2013 formally declared the city bankrupt but it won court approval to exit bankruptcy last November. Once the proud symbol of U.S. industrial strength, Detroit fell on hard times after decades of population loss, rampant debt and financial mismanagement left it struggling to provide basic services to residents. (Photo by Joshua Lott/Reuters)

Located in Kunshan, eastern China, the restaurant relies on over a dozen machines for tasks such as greeting customers, waiting on tables and cooking basic meals. The eatery becomes the third café in the world to rely on the use of robot employees, potentially giving a glimpse into how future businesses could operate. Photo: This photo taken on August 13, 2014, shows a robot carrying food to customers in a restaurant in Kunshan. It's more teatime than Terminator – a restaurant in China is electrifying customers by using more than a dozen robots to cook and deliver food. (Photo by Johannes Eisele/AFP Photo)

Performing arts titled “Solitude of Silences” by Gimhongsok is staged at Art Basel in Hong Kong, China on March 23, 2023. (Photo by Tyrone Siu/Reuters)

Human canvases modelling world famous artworks including Van Gogh's Sunflowers and Edvard Munch's The Scream take to the streets of London in a bid to mend Britain's disconnect with art on September 25, 2017. Award winning body paint artist Sarah Attwell was commissioned by online art platform Rise Art to show that great art is for everybody, following research that revealed 1 in 6 Brits have never set foot in an art gallery. (Photo by Imagewise Ltd/Rex Features/Shutterstock)

Attendees Rosalia Rohwer and Jennifer Salenger dress up as characters from the game “Just Dance” at E3, the world's largest video game industry convention in Los Angeles, California on June 12, 2018. (Photo by Mike Blake/Reuters)