Erin Brooks of Canada surfs in the Heat 3 of the Round of 16 during the 2024 GWM Sydney Surf Pro at North Narrabeen Beach on May 12, 2024 in Sydney, Australia. (Photo by Andy Cheung/Getty Images)

A youth in make-up waits for the start of the annual Zombie walk in Mexico City, Saturday, October 22, 2016. Hundreds dressed in rags and ghoulish makeup to look bloody and decaying, gathered in the historic center of Mexico's capital. (Photo by Christian Palma/AP Photo)

A woman made up as a skull participates in Day of the Dead festivities in Mexico City, Thursday, October 27, 2016. The holiday honors the dead as friends and families gather in cemeteries to decorate their loved ones' graves and hold vigil through the night on Nov. 1 and 2. (Photo by Marco Ugarte/AP Photo)

Balinese man dances in the middle of burn coconut husks during the fire fight ritual called Mesabatan Api on March 21, 2023 at traditional sub village of Nagi, in Gianyar, Bali, Indonesia. The mesabatan api ritual is held annually on the eve of Nyepi, the Hindu Day of Silence, the Balinese Caka New Year, and only takes place in Pakraman Nagi village in Gianyar regency, around 30 kilometers from Denpasar. (Photo by Agung Parameswara/Getty Images)

Skeletons are arranged in a bar scene as part of a competition to create Day of the Dead altars on pedestrian Regina Street in central Mexico City, Tuesday, November 1, 2016. The holiday honors the dead as friends and families gather in cemeteries to decorate their loved ones' graves and hold vigil through the night on Nov. 1 and 2. (Photo by Rebecca Blackwell/AP Photo)

St. Vincent performs at the Coachella Valley Music and Arts Festival in Indio, California, U.S., April 13, 201. (Photo by Mario Anzuoni/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.

A runner competes in the Great Wall Marathon at the Huangyaguan Great Wall outside Beijing, China, May 18, 2019. (Photo by Thomas Peter/Reuters)