Japan's Naomi Osaka returns the ball during her match against Slovakia's Dominika Cibulkova during the Madrid Open tennis tournament, Sunday, May 5, 2019, in Madrid, Spain. (Photo by Andrea Comas/AP Photo)

People run along a street as rain caused by tropical storm Alberto, the first named storm of 2024 Atlantic hurricane season, falls, in Monterrey, Mexico. on June 19, 2024. (Photo by Daniel Becerril/Reuters)

Judges watch athletes during the women's individual compact NH 5km competition at the Nordic Combined World Cup in Ramsau, Austria, Saturday, December 16, 2023. (Photo by Matthias Schrader/AP Photo)

Military officers look at an AR-10 sniper rifle at LAAD, the biggest military industry expo in Latin America in Sao Paulo, Brazil April 10, 2018. (Photo by Nacho Doce/Reuters)

Canoeists are framed by the tail of a breaching whale in Antarctica in April 2023. The photographer, from California, writes: “It was probably a once-in-a-lifetime moment”. (Photo by Jiahong Zeng/Solent News)

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.

Flamengo soccer fans cheer a goal scored by Gabriel against Argentina's River Plate in the Copa Libertadores final match, broadcast on a giant screen at a watch party at the Macarena Stadium, in Rio de Janeiro, Brazil, Saturday, November 23, 2019. The first single-match final will be played in front of more than 65,000 fans at Lima’s Monumental Stadium. The match was originally scheduled for Santiago’s National Stadium, but it was moved because of street protests in Chile. (Photo by Silvia Izquierdo/AP Photo)

United States's Jessie Diggins celebrates winning the cross-country ski, women's Tour de Ski overall standings, in Val di Fiemme, Italy, Sunday, January 7, 2024. (Photo by Alessandro Trovati/AP Photo)