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.

Maj. Matt O'Donnell of Glenelg, MD shields himself from rotor wash as Ospreys carrying the delegation of U.S. Secretary of Defense Leon Panetta leaves on March 14, 2012 at Forward Operating Base Shukvani, Afghanistan. Panetta is also scheduled to meet with President Karzai during his two-day visit to Afghanistan. The trip comes as the Taliban has vowed revenge following this past weekend's killing spree by a U.S. soldier who is accused of killing 16 civilians in Afghanistan. Most of those killed were children and women. (Photo by Scott Olson/Getty Images)

Saint Nicholas poses with students during a traditional parade in central Brussels, Belgium December 3, 2016. (Photo by Yves Herman/Reuters)

In this Friday, January 6, 2017, photo, a North Korean woman working at the Kim Jong Suk Silk Mill looks up from her workstation in Pyongyang, North Korea. The silk mill, named after North Korean leader Kim Jong Un's grandmother, is where 1,600 workers – mostly women – sort and process silkworms to produce silk thread that officials at the Pyongyang factory say is made into roughly 200 tons of silk a year. (Photo by Wong Maye-E/AP Photo)

Children play on top of an abandoned car at the “Aguerridos Liberator” shanty town in Caracas, Venezuela, Thursday, May 9, 2019. (Photo by Rodrigo Abd/AP Photo)

A couple kiss as strong waves hit the coast in Saint-Benoit, on the east of the French Indian Ocean island of La Reunion, on February 2, 2022, ahead of the passage of tropical cyclone Batsirai. La Reunion goes on red alert at 7 pm on February 2, to prepare for the likely passage of cyclone Batsirai overnight. The cyclone already left at least 7,500 homes in nearby Mauritius without power, after it brought heavy downpours and winds of around 120 kilometres per hour, knocking down trees onto electricity lines, according to the local electricity board. (Photo by Richard Bouhet/AFP Photo)

A Palestinian clown wearing a face mask while entertaining children at their home during the lockdown after the outbreak of the COVID-19 pandemic in Jabalia Refugee Camp in northern Gaza Strip on November 18, 2020. (Photo by Mahmoud Issa/Quds Net News/ZUMA Wire/Rex Features/Shutterstock)

Dressed in folk costumes, young women decorate a tree with painted Easter eggs in Dombrad, Hungary, Monday, April 5, 2021. (Photo by Attila Balazs/MTI via AP Photo)