Disguised participants strike poses on a car during the ancient carnival of Ituren, in the northern Spanish Navarra province on January 30, 2017. The yearly three day festivities, revolving mainly around agriculture and principally sheep hearding, run on the last Sunday, Monday and Tuesday of January where Navarra Valley locals from two villages dress up and participate in a variety of activites as they perform a pilgrimage through each village. (Photo by Ander Gillenea/AFP Photo)

Owner Elizabeth Wilson groomes her Chinese Crested and Coton De Tulear dogs during the annual Crufts Dog Show at the NEC Arena in Birmingham, Britain, March 10, 2016. The world's largest dog show will be held from March 10 to 13 with 22,000 dogs competing for the world class title of Crufts Best In Show. (Photo by Nigel Roddis/EPA)

People look up at a dead body hanged by the Taliban from a crane in the main square of Herat city in western Afghanistan, on Saturday September 25, 2021. A witness told The Associated Press that the bodies of four men were brought to the main square and three of them were moved to other parts of the city for public display. The Taliban announced in the square that the four were caught taking part in a kidnapping and were killed by police. (Photo by AP Photo/Stringer)

A child dressed as Hindu God Shiva begs for alms from devotees at the Sangam, the confluence of three rivers – the Ganges, the Yamuna and the mythical Saraswati, on the Makar Sankranti festival during the annual traditional fair of Magh Mela in Prayagraj, in the northern Indian state of Uttar Pradesh, Sunday, January 14, 2024. Hundreds of thousands of Hindu pilgrims are expected to take dips in the confluence, hoping to wash away sins during the month-long festival. (Photo by Rajesh Kumar Singh/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.

Wolfgang (L), member of World War One historical association “Darstellungsgruppe Suddeutsches Militar 1870-1918” (DSM 18), from Munich, Germany, and Florent, member of French association “Le Poilu de la Marne”, dressed in vintage army uniforms, visit the Bezonvaux bunker in the national forest of Verdun, eastern France, March 29, 2014. Members of French and German historical associations, who gather annually, together visited the battlefield of Verdun in France, the site of a bloody World War One battle that dragged on for around 10 months in 1916, claiming hundreds of thousands of lives and destroying many villages. (Photo by Charles Platiau/Reuters)

The solar eclipse is seen above the Washington Monument on April 08, 2024 in Washington, DC. People have traveled to areas across North America that are in the “path of totality” in order to experience the eclipse today. The next total solar eclipse that can be seen from a large part of North America won't happen until 2044. (Photo by Chip Somodevilla/Getty Images)

Women's Sabre Gold medalist Olga Kharlan (L) and bronze medalist in the Men's Greco-Roman Wrestling Zhan Beleniuk (R) react as they arrive at the railway station in Kyiv, Ukraine, 13 August 2024. Ukrainians meet and greet the members of National Olympic team as they return from Olympic Games 2024 in Paris amid the ongoing Russian invasion. (Photo by Sergey Dolzhenko/EPA/EFE)