Members of the Turkana community work unblocking an irrigation canal to provide water to their sorghum crops in an arid dry area in Nanyee, near Lodwar, Turkana County, Kenya, on October 1, 2019. Turkana is a vast, dry area in the north-west of Kenya that is on the frontline of climate change. With regular searing temperatures the Turkana people are suffering from recurring and prolonged droughts. (Photo by Luis Tato/AFP Photo)

East Berliners crossing into the West Berlin on November 11, 1989 at the Potsdamer Platz, Germany. (Photo by Kai Wiedenhoefer)

A woman walks depicting a scene from the Iranian national epic poem “Shahnameh” in Tehran on August 5, 2025. (Photo by Atta Kenare/AFP Photo)

Wearing hats and dancing to Sodapop. As the popularity of “K-Pop Demon Hunters (K-Pop Demon Hunters)” spreads around the world, foreign tourists wearing hats and dancing to the K-Pop Demon Hunters song “Sodapop” are seen in Gwanghwamun, Seoul on the afternoon of the August 29, 2025. (Photo by Park Seong-won)

Ocean Rebellion demonstrators perform on the Albert Embankment, on the final day of the MEPC 82 meetings in London, UK on October 2, 2024. (Photo by Victoria Jones/Rex Features/Shutterstock)

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.

Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/Reuters)