Flocks of seagulls swarm small fishing boats in the first decade of January 2024 like a scene from Alfred Hitchcock’s The Birds. Colonies of Heuglin’s gulls can be seen almost every morning on the Yamuna River in Delhi, India. (Photo by Raghav Rai Ralhan/Solent News)

An aerial drone photo shows a view of the Wujiangzhai scenic spot in Zunyi, southwest China's Guizhou Province, March 14, 2024. The Wujiangzhai scenic spot, with its natural landscape and local folk customs, offers a blend of sightseeing, leisure activities and exhibitions, making it a popular destination for tourists. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Drag king Riss Obolensky performs as drag king Norman Creebs during the Opening Cabaret at The London Clown Festival in London, Britain, on July 8, 2024. (Photo by Hollie Adams/Reuters)

Nasoin Akhter, 15, has her makeup done at a beauty parlor on the day of her wedding to a 32-year-old man, August 20, 2015, in Manikganj, Bangladesh. In June of this year, Human Rights Watch released a damning report about child marriage in Bangladesh. The country has one of the highest rates of child marriage in the world, with 29% of girls marrying before the age of 15, and 65% of girls marrying before they turn 18. (Photo by Allison Joyce/Getty Images)

Chincoteague Ponies swim across Assateague Channel in a heavy downpour on Wednesday, July 24, 2013 during the 88th Annual Chincoteague Pony Swim. A portion of the herd will be auctioned on Thursday. (Photo by Jay Diem/Eastern Shore News)

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.

A hot air balloon in the shape of children's comic Rupert Bear is seen tethered before a tethered flight at the Bristol International Balloon fiesta in south west England, Britain, August 10, 2018. (Photo by Adrian Sherratt/The Guardian)

Brides-to-be participate in the “Running of the Brides” race in a park in Bangkok, Thailand March 25, 2017. (Photo by Athit Perawongmetha/Reuters)