Pigeons cool down at a public fountain on a hot summer day at University Plaza in downtown Bucharest, Romania, 10 June 2020. Temperatures in Bucharest reached 30 degrees Celsius. (Photo by Robert Ghement/EPA/EFE)

This picture taken on May 24, 2019 shows Mariam the dugong as she is cared for by park officials and veterinarians from the Phuket Marine Biological Centre on Libong island, Trang province in southern Thailand. An orphaned baby dugong rescued off a beach in Krabi province is Thailand's newest star, capturing the hearts of millions on social media and igniting an awarness for ocean conservation as authorities hand-raise the young mammal. (Photo by Sirachai Sirachai Arunrugstichai/AFP Photo)

A Kathakali classical dancer (2L) watches artists rehearse the traditional folk dance Pulikkali (Tiger Dance) as they wait backstage before their performance at a cultural festival in Chennai on July 12, 2025. (Photo by R. Satish Babu/AFP 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 cat wering glasses lies in a pet dryer at the “Pet Expo Championship” in Bangkok, Thailand on August 30, 2019. (Photo by Mladen Antonov/AFP Photo)

Members of a teenage girl gang convincing an unwilling recruit to join the gang, circa 1955. (Photo by Vecchio/Three Lions)

An alligator named Muja is seen in its enclosure in Belgrade's Zoo, Serbia, August 14, 2018. Muja is officially the oldest American alligator in the world living in captivity. He was brought to Belgrade from Germany in 1937, a year after the opening of the Zoo. Muja survived three bombings of Belgrade, the Second World War and all hardships the Zoo went through. (Photo by Marko Djurica/Reuters)

A market trader in Gaibandha in Bangladesh on September 25, 2019, surrounded by bottle gourd vegetables, which sell for around 3p ($ 0.04) each. (Photo by Solent News)