The rabbit population of San Juan Island, brought in to feed lighthouse keepers, got so big that in the 1930s foxes were introduced to kill them. Although they are red foxes, their coats can be orange, silver, black or multi-coloured. Picture date: September 2023. (Photo by Jun Zuo/Solent News)

A leopard skin burns as Indian officials and activists burn wildlife contraband including tiger and leopard skins, and bones as part of a campaign to save the tiger in Mumbai, India, Tuesday, July 30, 2013. Despite conservation efforts, tiger numbers in India have declined due to rampant poaching of the cats for their valuable pelts and body parts that are highly prized in traditional Chinese medicine. (Photo by Rafiq Maqbool/AP Photo)

Erica Daly, a District Nurse Team Leader at Mersey Care NHS, stands in front of the “Liver Bird Wings”, an artwork by Paul Curtis on a wall within Liverpool's Baltic Triangle on April 29, 2020. (Photo by Peter Byrne/PA Images via Getty Images)

A participant of the Delhi Queer Pride Parade poses for a photograph during the march in New Delhi, India, Sunday, November 26, 2023. This annual event comes as India's top court refused to legalize same-sеx marriages in an October ruling that disappointed campaigners for LGBTQ+ rights in the world's most populous country. (Photo by Shonal Ganguly/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 Pasola rider reacts after throwing his spear during the Pasola war festival at Ratenggaro village on March 22, 2014 in Sumba Island, Indonesia. The Pasola Festival is an important annual event to welcome the new harvest season, which coincides with the arrival of “Nyale” sea worms during February or March each year. Pasola, an ancient ritual fighting game, involves two teams of men on horseback charging towards each other while trying to hit their rivals with “pasol” javelins and avoid being hit themselves. (Photo by Ulet Ifansasti/Getty Images)

A motorcycle-taxi driver takes a nap while leaning on his bike along a street in Bangkok, Thailand on February 17, 2019. (Photo by Jewel Samad/AFP Photo)

A green frog sits on a moth orchid at a local agricultural research center in Hwaseong, about 40 kilometers south of Seoul, South Korea, 03 March 2022, two days ahead of “gyeongchip”. On the lunar calendar, gyeongchip is the day when frogs awake from hibernation. (Photo by Yonhap/EPA/EFE)