A girl from Newar community is pictured with vermillion powder on her forehead as she takes part at the Ihi ceremony in Bhaktapur, Nepal on December 6, 2019. The two-day ceremony begins with purification rituals and ends with “Kanyadan” (giving away the virgin) of the girl by her father. A Newari girl gets married thrice in her life, first with Bel, the fruit of a wood-apple tree, secondly with the sun, and lastly with her future husband. (Photo by Monika Deupala/Reuters)

In this April 2, 2015 photo, dog owner Laura Aquilina strolls with her two year old Rottweiler Brutus, who was recently fitted with prosthetics on all four paws, and is currently learning to use them, near Aquilina's home in Loveland, Colo. Brutus lost all four paws to frostbite as a puppy while under care of a breeder, and Aquilina began caring for him about a year ago. (Photo by Brennan Linsley/AP Photo)

Revellers of street parties known as blocos, dance during a protest against restrictions by city officials in Rio de Janeiro, Brazil, Wednesday, April 13, 2022. City Hall has banned the street parties during Carnival celebrations, which were delayed by almost two months due to the pandemic. (Photo by Silvia Izquierdo/AP Photo)

A vendor sleeps as his son waits for customers at their roadside vegetable shop in New Delhi, February 12, 2019. (Photo by Adnan Abidi/Reuters)

A man is reflected in the water as he sleeps on the street in Kathmandu, Nepal, 27 June 2023. Despite the Meteorological Forecasting Division of Nepal already announcing the onset of the monsoon season in the country on June 14, 2023, the monsoon rainfall has not been significantly active yet. (Photo by Narendra Shrestha/EPA)

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.

“Honorable Mention”. An Indian rhinoceros, far from home and stuck inside with late-winter blues at the Toronto zoo. Photo location: Toronto, Ontario, Canada. (Photo and caption by Stephen De Lisle/National Geographic Photo Contest)

Omsin, a 25 year old femal green sea turtle, rests next to a tray of coins that were removed from her stomach after a surgical operation at the Faculty of Veterinary Science, Chulalongkorn University in Bangkok, Thailand, March 6, 2017. (Photo by Athit Perawongmetha/Reuters)