Revellers ride during the 54th annual brass band festival in the Serbian village of Guca August 7, 2014. Every year Guca is swamped by thousands of people taking part in the celebration of brass band music. (Photo by Marko Djurica/Reuters)

A woman wearing a burka walks through a bird market as she holds her child, in downtown Kabul, Afghanistan, Sunday, May 8, 2022. Afghanistan’s Taliban rulers on Saturday ordered all Afghan women to wear head-to-toe clothing in public – a sharp, hard-line pivot that confirmed the worst fears of rights activists and was bound to further complicate Taliban dealings with an already distrustful international community. (Photo by Ebrahim Noroozi/AP Photo)

Miss Colombia Ariadna Gutierrez, right, and Miss Philippines Pia Alonzo Wurtzbach wait for the announcer to name the new Miss Universe at the Miss Universe pageant on Sunday, December 20, 2015, in Las Vegas. Gutierrez was incorrectly crowned before Wurtzbach was named Miss Universe. (Photo by John Locher/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.

Italian disabled dancer Simona Atzori (top) performs, before a special audience with disabled athletes led by Pope Francis, in Paul VI hall at the Vatican October 4, 2014. (Photo by Tony Gentile/Reuters)

A couple embrace during the start of the San Fermin festival in Pamplona, Spain July 6, 2016. Revelers from around the world kick off the festival with a messy party in the Pamplona town square, one day before the first of eight days of the running of the bulls. (Photo by Vincent West/Reuters)

Mare Sorie, left, and her friend Tsehaynesh Golja, right, take a rest as they carry bundles of firewood from the forest around Entoto mountain near Addis Ababa, Ethiopia Friday, July 17, 2020. (Photo by Mulugeta Ayene/AP Photo)

An Afghan woman walks with a child in the old city of Herat province, Afghanistan on October 15, 2018. (Photo by Mohammad Ismail/Reuters)