Filipino typhoon survivor children, who escaped after their village was attacked by allegedly armed men, wait for social workers in the super typhoon devastated city of Tacloban, Leyte province, Philippines, 13 November 2013. Aid workers and relief supplies were being poured into eastern provinces hit by Typhoon Haiyan, which aid agencies and officials estimated has left thousands dead and staggering destruction in its wake. The official death toll in the Philippines from one of the world’s strongest typhoons rose to 1,833, the national disaster relief agency said with many towns still unaccounted for. (Photo by Dennis M. Sabangan/EPA)

“On March 8th activists celebrate International Women’s Day, which dates back to the early 20th century and has been observed by the United Nations since 1975. In the run-up to the event, Reuters photographers in countries around the globe took a series of portraits of women and their daughters. They asked each mother what her profession was, at what age she had finished education, and what she wanted her daughter to become when she grew up. They also asked each daughter at what age she would finish education and what she wanted to do in the future. The series of images offers an insight into the lives of women and girls around the world”. – Reuters. (Photo by Feisal Omar/Reuters)

British South American Airways hostess Mary Guthrie with a pair of pineapples, on the return of the Lancastrian airliner 'Star Dust' to Heathrow Airport after a test-flight to Buenos Aires, 15th January 1946

A little girl hangs three Siamese kittens on a washing line in a garden in Croydon, London. (Photo by Fox Photos/Getty Images). 14th July 1931

Medics carry an injured at the explosion site in the busy center of Turkish capital, Ankara, Turkey, Sunday, March 13, 2016. The explosion is believed to have been caused by a car bomb that went off close to bus stops. News reports say the large explosion in the capital has caused several deaths and many casualties. (Photo by 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.

Model Adriana Lima attends Madonna presents An Evening of Music, Art, Mischief and Performance to benefit Raising Malawi at Faena Forum on December 2, 2016 in Miami Beach, Florida. (Photo by Jeff Kravitz/FilmMagic for Raising Malawi)

Visitors crowd an artificial wave swimming pool at a tourist resort to escape the summer heat in Daying county of Suining, Sichuan province, China, July 11, 2015. (Photo by Reuters/Stringer)