Yoga enthusiasts perform a yoga exercise in a wine yoga class inside “Van Gogh: The Immersive Experience”, a multi-sensorial exhibition featuring artworks of renowned artist Vincent van Gogh at a department store in Bangkok, Thailand, August 5, 2023. (Photo by Athit Perawongmetha/Reuters)

A model holds a 18,18 carat pink diamond called “Fortune Pink” that could fetch 30 million U.S. dollars during a preview at Christie’s before the auction sale in Geneva, Switzerland on November 2, 2022. (Photo by Denis Balibouse/Reuters)

In this photo taken Wednesday, March 8, 2017, a hospitality staff member pose for photos near the shadow of a tall light pole near the Great Hall of the People where a plenary session of the National People's Congress is held in Beijing, China. (Photo by Ng Han Guan/AP Photo)

The Aletsch Glacier is pictured at dusk in Fiesch, Switzerland, August 11, 2015. One of Europe's biggest glaciers, the Great Aletsch coils 23 km (14 miles) through the Swiss Alps – and yet this mighty river of ice could almost vanish in the lifetimes of people born today because of climate change. The glacier, 900 metres (2,950 feet) thick at one point, has retreated about 3 km (1.9 miles) since 1870 and that pace is quickening. (Photo by Denis Balibouse/Reuters)

A cosplayer dressed as Batman wearing the Hellbat suit crosses the road during Day 1 of New York Comic Con at Javits Center on October 07, 2021 in New York City. Comic Con has returned this year after being cancelled in 2020 due to the coronavirus pandemic. (Photo by Alexi Rosenfeld/Getty Images)

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.

Tourists pay a visit to Edradour distillery on March 26, 2012 in Pitlochry, United Kingdom. (Photo by Jeff J. Mitchell/Getty Images)

A man stands next to his giant pumpkins as he waits for them to be weighed in at the 34th Annual Safeway World Championship Pumpkin Weigh-Off October 8, 2007 in Half Moon Bay, California. (Photo by Justin Sullivan/Getty Images)