Pooh, a one-year-old cat, who lost his hind legs in an accident and has been given bionic paws, walks in a vet clinic in Sofia on January 31, 2017. Pooh, who is thought to have lost his legs in a car or train accident last April, is back on the prowl thanks to Bulgarian veterinary surgeon Vladislav Zlatinov. He is the first vet in Europe to successfully apply the pioneering method of Irish neuro-orthopaedic surgeon Noel Fitzpatrick, who shot to fame in 2009 when making Oscar the first bionic cat by fitting him with new hind legs in Britain. (Photo by Nikolay Doychinov/AFP Photo)

The expertly colourised shots were brought to life by French bank technician, Frédéric Duriez (51). The images were provided by the Valois collection which belongs to the BDIC. “By colourising these photos, I reduce the time that separates us today from this conflict”, said Frédéric. Here: Car cannon sections in firing position, Auxi-le-Château. (Photo by Frédéric Duriez/BDIC/Mediadrumworld.com)

A bear that wandered into a University of Colorado Boulder dorm complex falls from a tree after being tranquilized by Colorado wildlife officials on April 26, 2012. Colorado wildlife official Jennifer Churchill said that the 200-pound male bear was tagged and relocated to a remote Rocky Mountain area. The bear was hit by two cars on May 3 and died. (Photo by Andy Duann)

Sixty four year old Hollywood movie stuntman Rock Taylor drives through a huge sheet of glass at the 02 Arena on September 13, 2011 in London, England. The stunt was performed in an attempt to break a previous Guinness record to “break through the Largest breakaway glass structure in a car”. The stunt was to mark “Remember a Charity” week, which aims to encourage more people to leave gifts to charity in their will. (Photo by Dan Kitwood/Getty Images)

A woman lies injured after an incident on Westminster Bridge in London on Wednesday, March 22, 2017. A police officer has been stabbed near to the British Parliament and the alleged assailant shot by armed police. Scotland Yard report they have been called to an incident on Westminster Bridge where several people have been injured by a car. (Photo by Toby Melville/Reuters)

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 1934 Packard Chassis Coachbuilt Body is displayed during The Quail, A Motorsports Gathering, in Carmel, California, U.S. August 19, 2016. The Pebble Beach Concours d'Elegance is an automotive charitable event held each year on the Pebble Beach Golf Links in Pebble Beach, California, considered the most prestigious event of its kind. It is the finale of Monterey Car Week held in August every year. (Photo by Michael Fiala/Reuters/Courtesy of The Revs Institute)

A 1949 Porsche 356 SL is displayed during the Porsche Rennsport Reunion V at Laguna Seca Raceway near Salinas, California, September 26, 2015. The three-day reunion is billed by organizers as the world's largest gathering of Porsche racecars, renowned drivers, and Porsche collector cars. (Photo by Michael Fiala/Reuters)