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.

Finding just the right spot above the clouds at Camp 1 on Ama Dablam, Danuru Sherpa uses his iPhone to catch up with friends and family. Even at 18,500 feet (5,654 meters), climbers here can check their email and other dispatches from the world below. (Photo by Aaron Huey/National Geographic)

“A Kind of You” is a documentary work of an uncanny asian tradition, where monkeys are trained and dressed to act humanlike in order to ask money from the bypassers. Modern city culture has turned the old tradition in to eerie and haunting act of cruel street theatre where animals become something else, never able to reach our expectations”. – Perttu Saksa. (Photo by Perttu Saksa)

SEE ALSO: «Topeng Monyet: The Masked Monkeys Of Indonesia»

Golden monkeys play at a conservation base in Shennongjia, central China's Hubei Province, January 26, 2018. The golden monkey conservation base witnessed a snowfall recently. (Photo by Du Huaju/Xinhua/Barcroft Images)

New York City Deputy Police Commissioner John A. Leach, right, watching agents pour liquor into sewer following a raid during the height of prohibition, circa 1921. (Photo by Tom Marshall/Mediadrumworld)

A child stands inside a large soap bubble made by a street artist at the Mayor square in central Madrid, Friday, December 9, 2016. (Photo by Francisco Seco/AP Photo)

Pod of dolphins surf effortlessly through the waves in the wild traveling at speeds up to 20 mph. (Photo by Greg Huglin)

Lawmakers fight around the rostrum during the first session of Ukraine's newly elected parliament in Kiev, Ukraine, December 13, 2012. (Photo by Sergei Chuzavkov/Associated Press)