Angel Hall, 22, (C) and Bri Artis, 21, (R) dance in a silent disco on the fourth and final day of the Firefly Music Festival in Dover, Delaware on June 17, 2018. (Photo by Mark Makela/Reuters)

A man passes by a wall with graffiti in Beirut, Lebanon, on May 29, 2019. (Photo by Bilal Jawich/Xinhua News Agency/Alamy Live News)

Revelers pose before the start of the Los Angeles Pride parade on June 9, 2019 in West Hollywood, California. The 49th annual parade, celebrating LGBTQ identity, drew thousands to the streets of West Hollywood. (Photo by Mario Tama/Getty Images)

Washington Nationals third baseman Anthony Rendon and reporter Alex Chappell are doused with water after the game against the Miami Marlins in Washington on August 30, 2019. (Photo by Brad Mills/USA TODAY Sports)

Birds congregate by the ocean at sunrise, after California’s governor said he would impose some of the nation’s strictest stay-at-home orders in the coming days, as the global outbreak of the coronavirus disease (COVID-19) continues, in Santa Monica, California, U.S., December 4, 2020. (Photo by Lucy Nicholson/Reuters)

A commuter gestures to Boris Johnson as he rides across Vauxhall Bridge in London, England on November 19, 2015. The London mayor was opening a cycle superhighway. (Photo by John Stillwell/PA Wire)

Meanwhile, over on Portobello beach, members of the Upsala circus take a stroll before their fringe debut, Ping-Pong Ball Effect in Edinburgh, England on August 1, 2017. (Photo by Murdo Macleod/The Guardian)

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.