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.

A woman waits to hear about her sister, a teacher, following a shooting at the Sandy Hook Elementary School in Newtown, Connecticut. A man killed his mother at their home and then opened fire inside the elementary school where she taught, massacring 26 people, including 20 children, as youngsters cowered in fear to the sound of gunshots reverberating through the building and screams echoing over the intercom. (Photo by Jessica Hill/Associated Press)

The rising sun illuminates the sky above the spires of a church in Vienna, Austria, November 17, 2015. (Photo by Heinz-Peter Bader/Reuters)

A Russian-made rifle, carried by this woman when she was captured in Nearby Brush, is slung around her neck by South Vietnamese soldiers before they began their interrogation of her as Viet Cong suspect near AP La Ghi in Vietnam, August 25, 1965. The girl behind the woman, also was captured in the brush. (Photo by AP Photo)

Indian youth practice a bike stunt ahead of a procession marking the annual Rath Yatra or chariot festival of Hindu deity Lord Jagannath in Ahmedabad, India, Wednesday, June 22, 2022. The festival is scheduled to be celebrated on July 1, 2022. (Photo by Ajit Solanki/AP Photo)

American actress Bella Thorne in the second decade of February 2023 nearly pours on out for “Italian Fashion”. (Photo by bellathorne/Instagram)

“Jimi Hendrix made it shriek. Buddy Holly made it swing. Stevie Ray Vaughn made it snarl. Some of the most legendary guitarists in music history have elicited unforgettable sounds from the Fender Stratocaster, the distinctive double-cutaway guitar born in a small Fullerton, Calif., workshop 60 years ago this month”. – Associated Press. Photo: A finished Fender Stratocaster is adjusted by Kenneth Maas in the Fender Custom Shop in Corona, Calif. on Tuesday, October 15, 2013. Leo Fender developed the instrument in a small workshop in Fullerton, Calif. six decades ago. (Photo by Matt York/AP Photo)

A couple joke as they walk on the beach on August 22, 2018 in Wonsan, North Korea. (Photo by Carl Court/Getty Images)