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.

Birds congregate by the ocean at sunrise, after California’s governor said he would impose some of the nation’s strictest stay-at-home orders in the coming days, as the global outbreak of the coronavirus disease (COVID-19) continues, in Santa Monica, California, U.S., December 4, 2020. (Photo by Lucy Nicholson/Reuters)

A instructor (2nd L) from the Philippine Mermaid Swimming Academy assists participants of a monofin swimming summer workshop as they practise floating in the water of a private pool in Paranaque city, metro Manila April 5, 2014. The Philippine Mermaid Swimming Academy workshops, which were originally conducted on the beaches of Boracay Island, central Philippines, currently cost 1,800 pesos per person ($40) for a two-hour session. (Photo by Romeo Ranoco/Reuters)

McMurdo Station is a U.S. Antarctic research centre located on the southern tip of Ross Island, which is in the New Zealand-claimed Ross Dependency on the shore of McMurdo Sound in Antarctica. It is operated by the United States through the United States Antarctic Program, a branch of the National Science Foundation. The station is the largest community in Antarctica, capable of supporting up to 1,258 residents, and serves as the United States Antarctic science facility. All personnel and cargo going to or coming from Amundsen–Scott South Pole Station first pass through McMurdo.

Sleeping Baby Bunny. A 6 day old baby bunny with mouth open while sleeping =D. Photo by Crezalyn Nerona Uratsuji

Street fighting in Berlin between Government troops and Spartacists, during the Spartacist uprising which followed Germany's defeat in World War I. (Photo by Keystone/Getty Images). 1919