In this April 12, 2015 photo, Sayed Ahmed Abdoh poles his boat to check his fish traps in the Nile River, near Abu al-Nasr village, about 770 kilometers (480 miles) south of Cairo, Egypt. Abdoh caught some 20 fish this day and gave them to his friend, Salama Osman, a migrant worker in a Cairo apartment building, to celebrate his biannual return to their village. (Photo by Hiro Komae/AP Photo)

A security exercise takes place along the River Thames on January 19, 2012 in London, England. The exercise including around 44 police officers, 94 military personnel, 15 boats and a Royal Navy Lynx helicopter was conducted by both the Metropolitan Police and the Royal Marines and designed to test their joint capability ahead of the 2012 London Olympic Games. (Photo by Dan Kitwood/Getty Images)

Revellers chase a bull into the sea during the “Bous a la Mar” festival on July 14, 2011 in Denia, Spain. The Spanish “Bous a la Mar” or “Bulls to the Sea” festival is held in honour of the Santisima Sangre and commemorate a monk named Pedro Esteve, who, as the legend has it, saved the coastal town of Denia from a plague in 1633. The bulls chased into the sea are later brought back to land by small boats. (Photo by Jasper Juinen/Getty Images)

Photographer David Lazar captured photos of native Dessana tribe, nearly 3,000 miles away from Brazil's capital. Tribe is only accessible by boat from city of Manaus. Surrounded by trees, waterfalls and tropical wildlife, this Amazon tribe is a world away from the beaches of Rio.

The Solar Impulse 2 airplane, flown by test pilot Markus Scherdel, flies off the coast of Oahu during a test flight from Kalaealoa Airfield in Kapolei, Hawaii, March 3, 2016. The solar-powered plane is ready to continue its revolutionary voyage around the world. After the craft was grounded in Hawaii last July due to overheated batteries, it was repaired and upgraded, and a recent initial test flight proved successful. (Photo by Eugene Tanner/Reuters)

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.

“Eclipse is a luxury motor yacht constructed by Blohm + Voss in Hamburg, Germany. Its exterior and interior were designed by Terence Disdale Design and its naval architect was Francis Design. The yacht was delivered to Russian businessman Roman Abramovich on 9 December 2010”. – Wikipedia

Photo: The Eclipse, reported to be the largest private yacht in the world, is viewed docked at a pier in New York on February 19, 2013 in New York City. The boat, which measures 557ft in length and is estimated to cost 1.5 billion US dollars, is owned by Russian billionaire Roman Abramovich and arrived into New York on Wednesday. (Photo by Spencer Platt)

Male orangutan Percy is reflected in the Sekonyer River as he reaches over to try and touch a wooden klotok boat carrying crew and tourists, in Tanjung Puting National Park, in Kalimantan (Indonesian Borneo), Indonesia, September 4, 2013. Percy is a son, born and living in the wild, of a female orangutan named Princess, a freed former captive orangutan that anthropologist Dr Birute Galdikas rescued, rehabilitated and returned to the wild. (Photo by Barbara Walton/EPA)