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.

Taronga Zoo's elephant baby, as yet unnamed, is seen at Taronga Zoo on March 12, 2010 in Sydney, Australia. The Asian Elephant calf has continued to make progress following a protracted labour that spanned six days. The calf was originally believed to have died in the womb during labour but surprised veterinarians and zoo staff with an unexpected delivery early Wednesday morning. (Photo by Bobby-Jo Vial/Taronga Zoo via Getty Images)

A Ukrainian man stands in protest in front of gunmen in unmarked uniforms as they stand guard in Balaklava, on the outskirts of Sevastopol, Ukraine, Saturday, March 1, 2014. (Photo by Andrew Lubimov/AP Photo)

Dancer Beth Bracegirdle of the Balbir Singh Dance Company practises at the Billingham Forum pool in Billingham, UK on July 20, 2016, ahead of the 52nd Billingham international folklore festival of world dance in August. (Photo by Owen Humphreys/PA Wire)

A young Chinese girl kicks during a kung-fu class at Ritan Park on June 11, 2016 in Beijing, China. Ritan, meaning “sun altar”, is among the oldest parks in Beijing, built in the early 1500s during the Ming dynasty for the emperor to make sacrifices to the sun. (Photo by Kevin Frayer/Getty Images)

Dog puppy “Sandy” protects against the rain with an umbrella fixed on her leash during a stroll in Rust, southern Germany, on May 26, 2013. (Photo by Patrick Seeger/AFP Photo)

“The Six-Day War or June War, also known as the 1967 Arab-Israeli War or the Third Arab-Israeli War, was fought between June 5 and June 10, 1967, by Israel and the neighboring states of Egypt (known then as the United Arab Republic [UAR]), Jordan, and Syria. The war began with a large-scale surprise air strike by Israel on Egypt. The outcome was a swift and decisive Israeli victory. Israel took effective control of the Gaza Strip and the Sinai Peninsula from Egypt, the West Bank and East Jerusalem from Jordan, and the Golan Heights from Syria. Opinions are divided on whether Israel's attack was an act of aggression or a preemptive strike of a defensive nature”. – Wikipedia

Photo: The corpse of a soldier lying on the line of the Israeli advance into Syria during the Six-Day War. (Photo by Terry Fincher/Getty Images). 1967

Costumed revellers walk in the streets of Lucerne during the annual carnival parade on Rose Monday March 3, 2014. (Photo by Sigi Tischler/AP Photo/Keystone)