New autopilot features are demonstrated in a Tesla Model S during a Tesla event in Palo Alto, California, 2015. Federal officials say the driver of a Tesla S sports car using the vehicle’s “autopilot” automated driving system has been killed in a collision with a truck, the first U.S. self-driving car fatality. The National Highway Traffic Safety Administration said preliminary reports indicate the crash occurred when a tractor-trailer made a left turn in front of the Tesla at a highway intersection. Joshua D. Brown, of Canton, Ohio, died in the accident May 7 in Williston, Florida, when his car's cameras failed to distinguish the white side of a turning tractor-trailer from a brightly lit sky and didn't automatically activate its brakes, according to government records obtained Thursday. (Photo by Beck Diefenbach/Reuters)

A string is used to ensure that the skirts of female members of the honour guard are in the same height from the ground as they prepare for a welcoming ceremony for Congo Republic President Denis Sassou Nguesso outside the Great Hall of the People in Beijing, China, July 5, 2016. (Photo by Jason Lee/Reuters)

Long shadows are cast by players as Mitch Wallis of the Bulldogs passes the ball during the 2016 AFL Round 08 match between the Melbourne Demons and the Western Bulldogs at the Melbourne Cricket Ground, Melbourne on May 15, 2016. (Photo by Scott Barbour/AFL Media/Getty Images)

In this May 24, 2018 file photo, rain drops accumulate on a car's windshield as commuters wait at a red light in Havana, Cuba. (Photo by Desmond Boylan/AP Photo)

An Afghan boy mourns next to the grave of his little brother who died due to an earthquake, in Zenda Jan district in Herat province, western of Afghanistan, Monday, October 9, 2023. Saturday's deadly earthquake killed and injured thousands when it leveled an untold number of homes in Herat province. (Photo by Ebrahim Noroozi/AP Photo)

A honour guard soldier gives a flower to a girl on International Women's Day in St. Petersburg, Russia, Friday, March 8, 2024. International Women's Day on March 8 is an official holiday in Russia. Per tradition, men give flowers and gifts to female relatives, friends and colleagues, even though in the past two years flowers have gotten more expensive. Marches, demonstrations and conferences are being held the world over, from Asia to Latin America and elsewhere. (Photo by Dmitri Lovetsky/AP Photo)

MSP Ash Regan and Lexie take part in Holyrood Dog of the Year on June 26, 2023 in Edinburgh, Scotland. At the annual contest, jointly organised by the Kennel Club and Dogs Trust, members of the Scottish Parliament compete with their dogs and Dogs Trust rescue dogs for the title of “Holyrood Dog of the Year”. (Photo by Jeff J. Mitchell/Getty Images)

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.