Attendees at Wizard World Comic Con walk through hallways in Chicago, Illinois, United States, August 22, 2015. (Photo by Jim Young/Reuters)

A Thai Yoga enthusiast performs during a mass yoga exercise in Bangkok, Thailand, 16 June 2019. Hundreds of Thai and foreign Yoga enthusiasts took part in the mass Yoga exercise organized by the Indian embassy to mark the International Day of Yoga which annually celebrated on 21 June. (Photo by Rungroj Yongrit/EPA/EFE)

Maj. Matt O'Donnell of Glenelg, MD shields himself from rotor wash as Ospreys carrying the delegation of U.S. Secretary of Defense Leon Panetta leaves on March 14, 2012 at Forward Operating Base Shukvani, Afghanistan. Panetta is also scheduled to meet with President Karzai during his two-day visit to Afghanistan. The trip comes as the Taliban has vowed revenge following this past weekend's killing spree by a U.S. soldier who is accused of killing 16 civilians in Afghanistan. Most of those killed were children and women. (Photo by Scott Olson/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.

American actress, model, and singer Ashley Benson arrives at Paris Hilton's wedding party inBeverly Hills, CA. on November 14, 2021. (Photo by Backgrid USA)

In this Friday, January 6, 2017, photo, a North Korean woman working at the Kim Jong Suk Silk Mill looks up from her workstation in Pyongyang, North Korea. The silk mill, named after North Korean leader Kim Jong Un's grandmother, is where 1,600 workers – mostly women – sort and process silkworms to produce silk thread that officials at the Pyongyang factory say is made into roughly 200 tons of silk a year. (Photo by Wong Maye-E/AP Photo)

Paris Jackson arrives at the Calvin Klein Collection fashion show during New York Fashion Week at New York Stock Exchange on February 13, 2018. (Photo by Ouzounova/Splash News and Pictures)