A canine chase a target during a racing competition on the outskirts of Charsadda on January 14, 2024. (Photo by Abdul Majeed/AFP Photo)

Pennsylvania's wildlife agency, firefighters and police use a large blue tarp to capture a wayward black bear as it falls from a tree Tuesday, June 4, 2024 in Camp Hill, Pa. (Photo by Sean Simmers/The Patriot-News via AP Photo)

This aerial view shows youths swimming to cool off in the waters of Iraq's Euphrates river during a heatwave, in the district of al-Hindiyah east of Karbala on June 7, 2024. (Photo by Karar Jabbar/AFP Photo)

A child reacts as a family takes a break next to a cooling mist at the Sensoji temple as Japanese government issued heat stroke alerts in 39 of the country's 47 prefectures in Tokyo, Japan on July 22, 2024. (Photo by Issei Kato/Reuters)

Handout photo provided by ParalympicsGB of Piers Gilliver competing in the Individual Sabre A - Men event during day six of the Paris 2024 Summer Paralympic Games on Tuesday, September 3, 2024. (Photo by ParalympicsGB/PA Wire)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

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.

Inside the Afar Triangle in Ethiopia’s Danakil desert, camel caravans are used to carry salt. For centuries, the essential mineral has been mined by the Afar people, known for their ability to withstand extremes. The terrain is rugged, travelers are scarce and so are motor vehicles, where the average annual temperature is the highest in the world, and can rise to 122 degrees Fahrenheit, 50 degrees Celsius. (Photo by Ziv Koren/Polaris)