A selection of hand-made leis, traditional Hawaiian necklaces made of flowers and worn mostly on special occasions, fill a cooler at Lin's Lei Shop in the Chinatown district of Honolulu, Hawaii December 22, 2015. Hawaii, whose economy depends heavily on tourism, sees a brief lull in visitors each year in January and February. But in addition to the usual tourist destinations, the state shows a unique overlay of mainland U.S. culture atop tropical beauty year-round. (Photo by Jonathan Ernst/Reuters)

Mercedes' British driver Lewis Hamilton (L) and Red Bull's Dutch driver Max Verstappen collide during the Italian Formula One Grand Prix at the Autodromo Nazionale circuit in Monza, on September 12, 2021. (Photo by Andrej Isakovic/AFP Photo)

Fifty years ago, as France exploded in mass protests, words scrawled on the walls of the Sorbonne summed up the revolutionary zeal of the time: “Run free, comrade, we’ve left the old world behind!”. Sexual liberation, artistic creativity and anti-capitalism were the order of the day. For those who were there, it was an unforgettable time. Here: A wounded student is transported by first-aid workers during riots on the Boulevard Saint-Michel, Paris, France on May 6, 1968. (Photo by Gökşin Sipahioğlu/SIPA Press)

Kendall Jenner (L) and Hailey Baldwin attend Harper's BAZAAR Celebration of “ICONS By Carine Roitfeld” at The Plaza Hotel presented by Infor, Laura Mercier, Stella Artois, FUJIFILM and SWAROVSKI on September 8, 2017 in New York City. (Photo by Bennett Raglin/Getty Images for Harper's BAZAAR)

A woman picks marigold flowers used to make garlands and offer prayers, before selling them to the market for the Tihar festival, also called Diwali, in Kathmandu, Nepal on October 17, 2017. (Photo by Navesh Chitrakar/Reuters)

Matilda Thurston 10, enjoys a warm day at Hathersage Swimming Pool in Hathersage on April 27, 2025. A mini heatwave is set to hit parts of the UK with temperatures reaching 27 degrees next week. (Photo by Ioannis Alexopoulos/London News Pictures)

A policeman kick in the door of a residence next to the Black Panther headquarters in New Orleans as they moved in following a shootout, September 15, 1970. Other heavily armed policemen stand at ready. (Photo by Jack Thornell/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.