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.

People walk on a sightseeing platform in Zhangjiajie, Hunan Province, China, August 1, 2016. China has opened a 100-metre-long glass skywalk stretching around a cliff on the side of the Tianmen Mountain. The skywalk provides a view of a 300-metre drop and overlooks Tongtian Avenue, a mountain road with 99 turns that snakes up the mountain. When translated in English, it means “Avenue to the Sky”. (Photo by Reuters/Stringer)

Elio Angulo (bottom C) lies inside a cardboard coffin next to Alejandro Blanchard as they introduce their product to potential customers at a mortuary in Valencia, in the state of Carabobo, Venezuela August 25, 2016. When Venezuelan entrepreneurs Alejandro Blanchard and Elio Angulo decided to create cardboard coffins, they were looking for an ecological selling point to compete against classic wood and brass caskets. Three years on, with the oil-rich country mired in deep economic crisis, their “bio-coffins” are becoming a viable option because of high prices for wooden coffins and shortages of brass ones. (Photo by Marco Bello/Reuters)

Each day as we look in the mirror, we think that we know ourselves. We are used to the image that we see before us, but the mirror can show us much more than we ever hoped to see. Sometimes it only shows basic emotions, while at other times it can highlight the deepest crevices of our soul. If you wish, in the reflection of the mirror you can see your deepest thoughts, masks that you wear every day, your desires, and of course the people that you think about. But are you brave enough to look deep within your soul? Will you dive headlong or shy away from your true image? Those that will muster up the courage necessary will realize it was well worth the effort. (Photo by Devin Mitchell)

“Sally Mann (born in Lexington, Virginia, 1951) is one of America’s most renowned photographers. She has received numerous awards, including NEA, NEH, and Guggenheim Foundation grants, and her work is held by major institutions internationally. Her many books include Second Sight (1983), At Twelve (1988), Immediate Family (1992), Still Time (1994), What Remains (2003), Deep South (2005), Proud Flesh (2009), and The Flesh and the Spirit (2010). A feature film about her work, What Remains, debuted to critical acclaim in 2006. Mann is represented by Gagosian Gallery, New York. She lives in Virginia”.

Photo: Candy Cigarette, 1989. (Photo by Sally Mann)

“The frilled shark (Chlamydoselachus anguineus) is one of two extant species of shark in the family Chlamydoselachidae, with a wide but patchy distribution in the Atlantic and Pacific Oceans. This uncommon species is found over the outer continental shelf and upper continental slope, generally near the bottom though there is evidence of substantial upward movements. It has been caught as deep as 1,570 m (5,150 ft), whereas in Suruga Bay, Japan it is most common at depths of 50–200 m (160–660 ft). Exhibiting several “primitive” features, the frilled shark has often been termed a «living fossil»”. – Wikipedia

Photo: A 1.6 meter long Frill shark swims in a tank after being found by a fisherman at a bay in Numazu, on January 21, 2007 in Numazu, Japan. The frill shark, also known as a Frilled shark usually lives in waters of a depth of 600 meters and so it is very rare that this shark is found alive at sea-level. It's body shape and the number of gill are similar to fossils of sharks which lived 350,000,000 years ago. (Photo by Awashima Marine Park/Getty Images)

Meirav Stardinner receives a snake massage from Ada Barak at Barak's snake spa on September 11, 2008 in Talmei Elazar, Israel. Barack's income comes mostly from exhibiting her plants which eat everything from insects to small mammals. She discovered snakes' therapeutic value after letting people hold them after her act “Some people said that holding the snakes made them feel better, relaxed”, she says. “One old lady said it was soothing, like a cold compress”. Now she uses a combination of big snakes for deep massage and little ones for light massage, though all are non-venemous. (Photo by Uriel Sinai/Getty Images)

Ukrainian artist Dariya Marchenko works on a portrait of Russian President Vladimir Putin named “The Face of War” which is made out of 5,000 cartridges brought from the frontline in eastern Ukraine, in Kiev, July 23, 2015. The portrait will be presented along with a novel which will tell personal stories of six people involved in this project including Daria's own story and stories of people who helped her to collect shells from the frontline. Daria Marchenko calls her art approach philosophic symbolism where every element has its hidden meaning. In her works cartridges mean human's life that was brutally ended. (Photo by Gleb Garanich/Reuters)