Tourists enjoy the rare opportunity to walk in water as they visit Badwater Basin, the normally driest place in the US, in Death Valley National Park, Inyo County, California on February 18, 2024. Badwater Basin, an endorheic basin in Death Valley National Park, was flooded by Hurricane Hilary in August 2023 and recent rains in California. It is the lowest point in North America, at 282 feet (86 meters) below sea level. (Photo by David Swanson/AFP Photo)

A boy takes his basset hound for a walk with a difference in Noosa, Australia on Saturday, March 9, 2024, during the annual Surf Dog Championships. (Photo by Roberta Holden/Solent News)

Staff members for U.S. Sen. Jeanne Shaheen (D-NH) push a stuffed moose into their office on Capitol Hill on June 11, 2024 in Washington, DC. A stuffed moose named “Marty the Moose” and a stuffed bear named “Kodak the Bear” will be on display in Shaheen's office as part of the thirteenth annual Experience New Hampshire event. (Photo by Andrew Harnik/Getty Images)

A participant wearing costumes takes part in the Pride Parade in Bangkok, Thailand, Saturday, June 1, 2024. Thailand is kicking off its celebration for the LGBTQ+ community's Pride Month with a parade on Saturday, as the country is on the course to become the first nation in Southeast Asia to legalize marriage equality. (Photo by Sakchai Lalit/AP Photo)

A Pakistani policeman wades across floodwaters in Lahore on August 19, 2024. Flash floods triggered by the latest spell of monsoon rains are wreaking havoc across parts of Pakistan, claiming the lives of 14 people in the previous 24 hours, an official at the provincial disaster management authority said on August 19. (Photo by Tahir Jamil Khan/Radio Free Europe/Radio Liberty)

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.

Apple CEO Tim Cook discusses the new iPhone 6 and iPhone 6 plus on Tuesday, September 9, 2014, in Cupertino, Calif. The iPhone 6 will have a screen measuring 4.7 inches, while the iPhone 6 Plus will be 5.5 inches. (Photo by Marcio Jose Sanchez/AP Photo)

The new curvy Barbie doll body shape (L) is seen next to the traditional Barbie in a combination of photos released by Mattel on January 28, 2016. Barbie, the world's most famous doll, has a new body. In fact, she has three new bodies – petite, tall and curvy. Some 57 years after the impossibly busty and narrow-waisted blue-eyed Barbie doll was first introduced, California-based toy maker Mattel on Thursday released the new models, which it says better reflect a changing world. (Photo by Reuters/Mattel)