Japanese chorus girls appear to be drilling in military tactics atop their theater building as they perform salutes, June 30, 1937. The officer is from the Japanese regular army and says the girls display more rhythm in their drills than do the regular troops. (Photo by AP Photo)

(L-R) American rappers Doja Cat and Tyga perform on the Coachella stage during the 2022 Coachella Valley Music And Arts Festival on April 24, 2022 in Indio, California. (Photo by Amy Sussman/Getty Images for Coachella)

Afghan children buy breads from a bakery in Fayzabad of Badakhshan province on February 7, 2024. (Photo by Omer Abrar/AFP Photo)

Visitors take photos of Fu Bao, a giant panda, at Everland amusement park in Yongin, south of Seoul, South Korea, 25 February 2024. The panda will be displayed to the public until 03 March, before returning to China in early April. The female panda, which was born to giant panda Ai Bao and her partner, Le Bao, at the Everland amusement park in Yongin, south of Seoul, in 2020, will be returned to China under an international agreement. (Photo by Yonhap/EPA)

Bride Fan Huixiang (front R), a 25-year-old cancer patient, receives flowers from nurses on her bed before her wedding ceremony at a hospital in Zhengzhou, Henan province November 17, 2014. Fan was diagnosed with late stage adenocarcinoma, a type of cancerous tumor, at her thoracic vertebra this June. She and her 24-year-old husband Yu Haining held their wedding ceremony at the hospital on Monday after five years of relationship, local media reported. (Photo by Reuters/China Daily)

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.

An upside-down pair of pants is seen atop a mound of snow, Wednesday, February 20, 2019, the result of yet another snow storm to hit Omaha, Neb. The latest winter storm dumped more snow on top of the existing snow, creating a problem of what to do with all the cleared snow. (Photo by Nati Harnik/AP Photo)