Twenty-four-year-old Maryam Aghayee makes hyper-realistic baby dolls acting as surrogates for some Iranian families who are apprehensive of having more children. “It has been about three or four months since I started this work”, says Maryam in Tehran, Iran on October 7, 2020. “After making my second doll, many orders have been coming in. The second doll was much more realistic than the previous one. After making my second doll, I said that from now on I can take customer orders. I did not intend to start a business from the beginning because it was a hobby, but after the second doll, the demand for these kinds of dolls increased, customers want to have such dolls”. (Photo by Majid Asgaripour/WANA (West Asia News Agency) via Reuters)

Boys pan for gold on a riverside at Iga Barriere, 25 km (15 miles) from Bunia, in the resource-rich Ituri region of eastern Congo February 16, 2009. Ituri is one of many areas of the country to have experienced bitter ethnic conflict between rival tribes in recent years. Massacres have left tens of thousands dead. It is this fighting that led U.S. authorities to take the unprecedented step of naming Congo in section 1502 of the Dodd-Frank financial regulation act, which says U.S.-listed companies that source gold, tungsten, tantalum and tin from Congo or its neighbours must assure the U.S. stock exchange regulator that their business is not helping fund conflict. (Photo by Finbarr O'Reilly/Reuters)

Macaque monkeys crowd together in their cage at a monkey farm on February 3, 2016 in Xinye county, Henan province, China. The area boasts a centuries-long and lucrative history of raising and training monkeys for performance. In Xinye, villagers are seeing an increase in business with the lunar calendar's “Year of the Monkey”. Farmers say most of the monkeys are bred and raised for domestic zoos, circuses, and performing groups, but add that some are also sold for medical research in China and the United States. Despite the popularity of the tradition, critics contend the training methods and conditions constitute animal cruelty. (Photo by Kevin Frayer/Getty Images)

A youth poses while holding two fishes before his face in Iraq's southern port city of al-Faw, 90 kilometres south of Basra near the Shatt al-Arab and the Gulf, on May 18, 2020. In Iraq, a national lockdown to halt the COVID-19 coronavirus pandemic has found some unexpected fans: local businesses who no longer have to compete with Turkish, Iranian or Chinese imports. Those countries, as well as Saudi Arabia, Jordan and Kuwait, typically flood Iraqi markets with inexpensive products at prices local producers can't compete with. (Photo by Hussein Faleh/AFP Photo)

The Mano de Desierto is a large-scale sculpture of a hand located in the Atacama Desert in Chile, 75 km to the south of the city of Antofagasta, on the Panamerican Highway. The nearest point of reference is the “Ciudad Empresarial La Negra” (La Negra Business City). The sculpture was constructed by the Chilean sculptor Mario Irarrázabal at an altitude of 1,100 meters above sea level. Irarrázabal used the human figure to express emotions like injustice, loneliness, sorrow and torture. Its exaggerated size is said to emphasize human vulnerability and helplessness. The work has a base of iron and cement, and stands 11 metres (36 ft) tall. Funded by Corporación Pro Antofagasta, a local booster organization, the sculpture was inaugurated on March 28, 1992.

Assistant Manager Jayesh Vaghela brushes a vintage silk top hat at Lock & Co. Hatters on March 22, 2011 in London, England. Founded in St. James's in 1676, when Charles II was on the throne, this family owned business has provided hats for Royalty and the gentry for over 300 years. Staff report that sales of formal hats are booming ahead of the wedding of Prince William and Kate Middleton in Westminster Abbey on April 29, 2011.

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)

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.