Libyan forces allied with the U.N.-backed government fire weapons during a battle with IS fighters in Sirte, Libya, July 21, 2016. (Photo by Goran Tomasevic/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.

British singer Rita Ora performs during the 43rd annual Gay and Lesbian Mardi Gras parade at the SCG in Sydney, Australia, 06 March 2021. (Photo by Dan Himbrechts/EPA/EFE)

Relatives of the Afghan Army soldiers, who are trapped in Obde district of Herat while fighting against Taliban militants, protest to demand the government evacuate the injured soldiers, in Herat, Afghanistan, 17 June 2021. Afghan authorities said they are in the process to arrange the evacuation of Army soldiers from the restive district soon. There has been a particularly bloody spike in violence in the country in recent weeks, following the start of the withdrawal of US troops from the country, a process due to be complete by September 11. (Photo by Jalil Rezayee/EPA/EFE)

First year cadets of the Vladivostok branch of Russian Internal Affairs Ministry's Far Eastern Law Institute march in formation during a ceremony to take oath of allegiance at a monument to Internal Affairs Ministry officers who lost their lives in line of duty in Vladivostok, Russia on September 24, 2021. 27 cadets took oath of allegiance during the ceremony. (Photo by Yuri Smityuk/TASS)

A man crosses a mud-covered trail carrying his wife on his back at a flooded Han River park in Seoul, South Korea, August 4, 2020. (Photo by Kim Hong-Ji/Reuters)

A young Sandinista guerrilla takes aim with his 45 pistol as he stands waiting to do combat with the Nicaraguan National Guard in Managua June 23, 1979. The guerrillas still occupy major parts of the Capitol City. (Photo by McLendon/AP Photo)

Linda Evangelista, Naomi Campbell, Polly Mellon, and Christy Turlington, The Fashion Group International's 6th Annual “Night of 100 Stars” at the The Plaza Hotel in New York City, New York on October 29, 1989. (Photo by Ron Galella/WireImage)