A baby Sumatran orangutan is bathed after arriving at a wildlife center at Ratchaburi province in Thailand September 13, 2017. (Photo by Kerek Wongsa/Reuters)

Sudanese fishermen check their boats and nets before they row through the waters of Nile River near Jebel Aulia, Sudan, May 3, 2019. (Photo by Umit Bektas/Reuters)

Miss Talavera Bruce 2017, Mayana Rosa Alves, right, takes a cigarette break with two contestants before the start of the 13th annual Miss Talavera Bruce beauty pageant at the penitentiary the pageant is named for, in Rio de Janeiro, Brazil, Tuesday, December 4, 2018. Prison authorities say they organize the annual beauty contest to encourage self-esteem, fight idleness and promote integration among the female inmates. (Photo by Silvia Izquierdo/AP Photo)

Women jump into the water during a traditional New Year bath in the Adriatic sea in Portoroz, Slovenia on January 1, 2018. (Photo by Jure Makovec/AFP Photo)

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.

The newly-discovered gaseous planet Kepler-16b orbits it's two stars. NASA's Kepler Mission discoverd the world orbiting two Stars, the larger a K dwarf and the smaller a red dwarf. (Photo by NASA/JPL-Caltech/T. Pyle via Getty Images)

A biker passes by a pair of mailboxes in the Capitol Hill neighborhood November 6, 2012 in Denver, Colorado. Colorado is considered by most experts to be one of the key battleground state in this year's presidential election. (Photo by Marc Piscotty/AFP Photo)

“MS Herald of Free Enterprise was a roll-on roll-off (RORO) car and passenger ferry owned by Townsend Thoresen. She was one of three ships commissioned by the company to operate on the Dover–Calais route across the English Channel. The ferry capsized on the night of 6 March 1987, moments after leaving the Belgian port of Zeebrugge, killing 193 passengers and crew. This was the deadliest maritime disaster involving a British ship in peacetime since the sinking of the Iolaire in 1919”. – Wikipedia

Photo: The wreck of the Herald of Free Enterprise, which capsized near Zeebrugge on the 6th of March 1987. (Photo by Hulton Archive/Getty Images). 1987