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.

A fisherman carries a silver carp during a traditional fish haul at the Horusicky pond near the town of Veseli nad Luznici, Czech Republic, Tuesday, October 24, 2017. Each autumn, Czech fishermen get to serious business of a century-long tradition of catching carp for Christmas markets. Southern Bohemia, where the Horusicky pond is located, with its elaborate network of ponds is at the center of the local carp universe. (Photo by Petr David Josek/AP Photo)

Rescue specialists for USA-1 drill through a concrete slab to rescue a victim from the scene of a mock disaster area during a training exercise at the Guardian Center in Perry, Georgia, March 25, 2014. A week of field training, the first of its kind at the 830-acre training site, to be open to the media, began Monday with the arrival of USA-1 from Fairfax, Virginia along with its sister team in Los Angeles, California. USA-1 has been deployed by the U.S. Agency for International Development to 30 foreign disasters, including earthquakes in Haiti, Armenia and Iran, the tsunami in Japan and the typhoon in the Philippines. (Photo by Shannon Stapleton/Reuters)

This undated image provided by World View shows World View capsule and balloon spacecraft that will rise to 100,000 feet above Earth for passengers to see the curvature of the planet and the blackness of space. Space tourism companies are employing designs including winged vehicles, vertical rockets with capsules and high-altitude balloons. While developers envision ultimately taking people to orbiting habitats, the moon or beyond, the immediate future involves short flights into or near the lowest reaches of space without going into orbit. (Photo by World View via AP Photo)

“A fter the former Soviet Union conducted its first nuclear test in August 1949, the US reevaluated its postwar defense policies. With the US monopoly on atomic weapons broken, military and political leaders chose to diversify the American stockpile by developing thermonuclear and tactical nuclear weapons. One of the more interesting concepts to come out of this period was atomic artillery, which was successfully tested at the Nevada Proving Grounds (now the Nevada Test Site) in May 1953”. – Alan Carr. Photo: Atomic Annie at work during the Upshot-Knothole test series, 1953. (Photo by Los Alamos National Laboratory/US Army)

A vendor (C) cuts slaughtered dogs for sale at his roadside stall in Duong Noi village, outside Hanoi December 16, 2011. While animal rights activists have condemned eating dog meat as cruel treatment of the animals, it is still an accepted popular delicacy for some Vietnamese, as well in some other Asian countries. Duong Noi is well-known as a dog-meat village, where hundreds of dogs are killed each day for sale as popular traditional food. Dog-eating as a custom is rooted in Vietnam and was developed as a result of poverty. One kilogram of dog meat costs about 130,000 dongs ($6.2). (Photo by Reuters/Kham)

“SpaceShipOne was a suborbital air-launched spaceplane that completed the first manned private spaceflight in 2004. That same year, it won the US$10 million Ansari X Prize and was immediately retired from active service. Its mothership was named “White Knight”. Both craft were developed and flown by Mojave Aerospace Ventures, which was a joint venture between Paul Allen and Scaled Composites, Burt Rutan's aviation company. Allen provided the funding of approximately US$25 million”. – Wikipedia

Photo: A chase plane follows SpaceShipOne after it reached a height of 62 miles in the first non-governmental flight to leave the Earth's atmosphere on June 21, 2004 in Mojave, California. SpaceShipOne spacecraft was carried to a height of 50,000 by the twin-turbojet high-altitude research aircraft, “White Knight”, where it was launched for its final climb. The space effort was funded by Microsoft co-founder Paul Allen and headed by aerospace engineer Burt Rutan. (Photo by Jim Campbell-Pool/Getty Images)

“I was born in 1977 in Warsaw, Poland. I had graduated from the High School of Art in Warsaw. My journey into the world of photography began in the early 90's, but at that time my biggest passion was painting. Painting helped me develop vision that was hard to create. Unfortunately I had to leave the paintbrush and canvas. A few years ago, I opened “the door” to my own world with help of a different key”... – Michal Karcz. Photo: “Last Outpost”. (Photo by Michal Karcz)