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 woman uses a virtual reality (VR) headset to view images by Mexican painter Frida Kahlo in Mexico City, Mexico, 23 May 2018. The technological giant Google launched the “The Faces of Frida”, an interactive digital exhibition that treasures the heartrending work of the Mexican artist to tell her story from different points of view, with attention to the invisible details. (Photo by Sashenka Gutierrez/EPA/EFE)

Gigi Hadid and Emily Ratajkowski celebrated the opening of the shopping centre by taking part in the evening's ribbon cutting ceremony in Mykonos, Greece on June 30, 2018. (Photo by Richard Young/Rex Features/Shutterstock)

For France, the trauma of the Algerian War (1954-1962) was not unlike the experience of the Vietnam War for the United States. But, unlike the conflict in Vietnam, few photographic documents exist from that period in Algeria: it is as if the French responded with collective amnesia. Marc Garanger’s Algerian Women is one of the few photographic essays dedicated to that painful period... Photo: A 1960 photograph of an Algerian woman in a French regroupment village. (Photo by Marc Garanger)

Hermes Cifuentes, who is also known as “Brother Hermes”, performs an exorcism on Marleny Munoz, 55, who claims to be possessed by spirits in La Cumbre, Valle July 7, 2012. Cifuentes says he has performed more than 35,000 exorcism rituals in the past 25 years. (Photo by Jaime Saldarriaga/Reuters)

Cannabis had already dominated the world of medicine. More and more people become convinced of its effectiveness, especially in terms of treating known diseases (e.g., Epilepsy, Depression, and Anxiety). Such commotion resulted in several experts to create and establish pieces of research about cannabis. Factors affecting the pros and cons are identified and verified to know further whether or not it is a capable substance.

A sign is posted in front of the new Yoga Room at San Francisco International Airport's terminal two on January 26, 2012 in San Francisco, California. (Photo by Justin Sullivan/Getty Images)

A worker distributes electronic waste at a government managed recycling centre at the township of Guiyu in China's southern Guangdong province June 10, 2015. The town of Guiyu in the economic powerhouse of Guangdong province in China has long been known as one of the world’s largest electronic waste dump sites. At its peak, some 5,000 workshops in the village recycle 15,000 tonnes of waste daily including hard drives, mobile phones, computer screens and computers shipped in from across the world. (Photo by Tyrone Siu/Reuters)