A seven week old Daschund cross puppy waits to be re-homed at the Cheshire Dogs Home on January 4, 2010 in Warrington, England. (Photo by Christopher Furlong/Getty Images)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)

Though it is often said that the human eye can be revealing about a person, Jakarta-based Indonesian artist Veri Apriyatno's series titled The Witnesses reveals a lot more about a person's surroundings through the reflection of their eyes. Each hyperrealistic mixed media creation in the series (made with charcoal, pencil, and acrylics on canvas) presents an entire world within the gaze of a glistening eye.

Samurai commiting seppuku (hara-kiri) in Japan, circa 1880. (Photo by adoc-photos/Corbis via Getty Images)

South Korean football fans react during a public screening in Seoul of the South Korea vs Russia football match at the 2014 World Cup in Brazil, early on June 18, 2014. (Photo by Ed Jones/AFP Photo)

Kim Kardashian looks to have left her underwear at home as she heads out for an early dinner with boyfriend Kanye West in Miami on October 14, 2012. As Kim checked out her outfit in the reflection of her car, it became apparent that the reality star was not wearing any underwear as she showed off her see-through grey skirt. (Photo by Brett Kaffee/Thibault Monnier/PacificCoastNews.com)

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.

The National parks department hosts the 30th annual “All-Women Lifeguard Tournament” in Sandy Hook NJ. July 30, 2014. (Photo by Anthony Causi)