Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Police detain a woman during a protest against Prime Minister Benjamin Netanyahu and his government's handling of the coronavirus disease (COVID-19) crisis, near Netanyahu's residence in Jerusalem on July 24, 2020. Reimposed coronavirus curbs after a rise in new COVID-19 cases have prompted Israelis demanding better state aid to take to the streets in almost daily demonstrations. Public anger has also been fueled by corruption alleged against Netanyahu, who went on trial in May for bribery, fraud and breach of trust – charges he denies. (Photo by Ammar Awad/Reuters)

Kiritimati is a far-flung outpost of the Republic of Kiribati. The world's largest coral atoll, Kiritimati has just one flight a week to either Fiji or Hawaii, four-and-a-half hours in either direction. Tarawa, the capital of Kiribati lies nearly 3,300 km (2,000 miles) to the west – about three weeks by boat. No lawyers are based on Kiritimati and the High Court only comes once or twice a year to clear a backlog of the most serious cases, bringing a public lawyer for defendants who can't afford their own. (Photo by Lincoln Feast/Reuters)

A girl sticks out her tongue during snowfalls on a street in Hefei, Anhui province February 13, 2014. (Photo by Reuters/Stringer)

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.

An empty beer bottle stands in front of the buildings of the banking district in Frankfurt, Germany, Friday, May 21, 2021. All people gathering on the square for drinks and food left when the police started checking if they are abiding by the coronavirus restrictions. (Photo by Michael Probst/AP Photo)

Vehicles are burning as thousands of people take to the streets during the May Day demonstrations on May 1, 2018 in Paris, France. This month celebrates the 50th anniversary of May 68 when France seen millions of students and striking workers, come onto the streets in demonstrations that changed the country. (Photo by Jeff J. Mitchell/Getty Images)

Mave Grace, 11, who had part of her arm chopped off by militiamen when they attacked the village of Tchee, stands with her sister Racahele-Ngabausi, aged two, in an Internally Displaced Camp in Bunia, Ituri province, eastern Democratic Republic of Congo, April 12, 2018. (Photo by Goran Tomasevic/Reuters)