Exhausted grave diggers rest in between funerals at a cemetery designated for Covid-19 victims in Bandung on June 15, 2021, as infection numbers soar in Indonesia. (Photo by Timur Matahari/AFP Photo)

A torch bearer poses for photographs during the Olympic Torch Relay Celebration event on July 21, 2021 in Tokyo, Japan. As the Olympic torch relay makes its way around Tokyo, public relays have been cancelled in favour of daily ceremonies held behind closed doors, as authorities act to avoid large gatherings while the country endures a fourth wave of coronavirus. (Photo by Yuichi Yamazaki/Getty Images)

A large brawl breaks out as people leave the track after Sydney Racing at Rosehill Gardens on December 07, 2019 in Sydney, Australia. (Photo by Mark Evans/Getty Images)

A guest dressed as a zombie attends the Middle East Film & Comic Con (MEFCC) in Gulf emirate of Dubai, United Arab Emirates, 11 April 2019. The event runs until 13 April 2019. (Photo by Ali Haider/EPA/EFE)

A gilrl plays games in a shopping mall in Beijing, China, 24 November 2021. Demographers in China have called for more efficient implementation of supportive measures to encourage births to address the country's dwindling population growth as country's birthrate last year was 8.52 births per thousand people, the lowest level since 1978, according China Statistical Yearbook 2021. (Photo by Wu Hong/EPA/EFE)

Indonesian soldiers wearing facemasks and personal protective equipment take a part in a sack race during games to celebrate ahead of the country's 75th Independence Day in Surabaya, East Java on August 14, 2020. Indonesia will mark its 75th Independence Day on August 17. (Photo by Juni Kriswanto/AFP Photo)

A girl bathes to cool off herself with water that is leaking from a broken pipe valve on a hot summer day on the outskirts of Ahmedabad, India, May 18, 2015. (Photo by Amit Dave/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.