A boy attends Eid al-Adha prayers on the street outside Abu Hanifa mosque in Baghdad Adhamiya district, during the outbreak of the coronavirus disease (COVID-19), in Iraq, July 31, 2020. (Photo by Thaier Al-Sudani/Reuters)

A Flame Skimmer or Firecracker Skimmer dragonfly (Libellula saturata) rests on a small branch in Topanga, California, USA, 18 June 2018. The Flame Skimmer dragonfly is found in the Western United States near ponds and creeks. (Photo by Mike Nelson/EPA/EFE)

An alpaca chewing a leaf is pictured on November 18, 2014 in the zoo of Frankfurt am Main, Germany. (Photo by Frank Rumpenhorst/AFP Photo/DPA)

A displaced man cools off to avoid heat on flooded highway, following rains and floods during the monsoon season in Sehwan, Pakistan on September 16, 2022. (Photo by Akhtar Soomro/Reuters)

Members of the Moroccan Royal Armed Forces Rescue and Relief Unit take part in a biochemical simulation organized by the US Defense Threat Reduction Agency (DTRA) as part of the “African Lion” military exercise, in the port of Agadir, on June 15, 2021. (Photo by Fadel Senna/AFP Photo)

A woman refreshes at a fountain in Casa de Campo during a heatwave in Madrid, Spain on June 15, 2022. (Photo by Isabel Infantes/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.

Mariam Emad from Parkour Egypt “PKE” practices her parkour skills around buildings on the outskirts of Cairo, Egypt on July 20, 2018. A group of Egyptian women gather at an abandoned park in a Cairo suburb once a week, climbing walls and jumping around in the strenuous physical discipline known as Parkour, while also challenging the country's conservative social norms. (Photo by Amr Abdallah Dalsh/Reuters)