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.

Swiss police officers stand beside of mock gates of the NEAT Gotthard Base Tunnel inside the event hall for the upcoming opening ceremony near the town of Erstfeld, Switzerland May 31, 2016. The celebrations of the opening of the Gotthard Base Tunnel will start on June 1, 2016. With a length of 57 km (35 miles) crossing the Alps, the Gotthard Base tunnel is the world's longest train tunnel. (Photo by Arnd Wiegmann/Reuters)

Chincoteague Ponies swim across Assateague Channel in a heavy downpour on Wednesday, July 24, 2013 during the 88th Annual Chincoteague Pony Swim. A portion of the herd will be auctioned on Thursday. (Photo by Jay Diem/Eastern Shore News)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

A woman hangs red chillies to dry outside her house at Khokana village on the outskirts of Kathmandu on August 5, 2020. (Photo by Prakash Mathema/AFP Photo)

A woman looks at artwork called “Alphabetti Spaghetti” by British sculptor Alex Chinneck, one of a series of “knotted” postboxes, installed as part of a public art trail for Kensington & Chelsea Art Week on October 3, 2020. (Photo by Victoria Jones/PA Images via Getty Images)

Indian women paint miniature models of houses as they make them for sale ahead of Diwali festival, in Prayagraj, India, Thursday, November 12, 2020. People buy them to decorate their homes during Diwali, the annual Hindu festival of lights which will be celebrated on Nov 14. (Photo by Rajesh Kumar Singh/AP Photo)

Motorcycle enthusiast Gilbert Delos Reyes rides with his pet dog Bogie, in Kawit, Cavite, Philippines, November 26, 2020. (Photo by Eloisa Lopez/Reuters)