Stanford golfer Rose Shang smiles towards her teammates after winning the NCAA college women's golf championship at Grayhawk Golf Club, Monday, May 22, 2023, in Scottsdale, Ariz. (Photo by Matt York/AP Photo)

A family rides a bike amid rain in Lahore on October 16, 2023. (Photo by Arif Ali/AFP Photo)

Kaori Sakamoto, of Japan, performs her women's short program during the Skate Canada International figure skating competition in Vancouver, British Columbia, Friday, October 27, 2023. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

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)

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 National Bolivarian Police officer rescues a man who was being attacked by protesters, who then threw rocks at them, during a protest demanding food a few blocks from Miraflores presidential palace in Caracas, Venezuela, Thursday, June 2, 2016. Venezuela is seeing rising frustration with widespread food shortages and triple-digit inflation. (Photo by Fernando Llano/AP Photo)

This picture taken on July 9, 2013 shows heavy flood waters sweeping through Beichuan in southwest China´s Sichuan province. Rainstorms sweeping across parts of China have affected millions, causing landslides and disabling transportation in provinces such as Sichuan and Yunnan, state media reported. (Photo by AFP Photo)

A vendor holds a teddy bear for sale on Valentine's Day in Port-au-Prince, Haiti, Monday, February 14, 2022. (Photo by Joseph Odelyn/AP Photo)