Two stallions confront each other at a horse fighting contest in Rongshui, China. More than 30 horses from surrounding regions took part in the traditional activity of the Lantern festival. (Photo by China Foto Press)

Nadezhda Sergeeva, of the Russian Olympic Committee, looks at her time in the women's monobob heat 4 at the 2022 Winter Olympics, Monday, February 14, 2022, in the Yanqing district of Beijing. (Photo by Pavel Golovkin/AP Photo)

A woman takes a picture of a sculpture depicting servant Puck from Shakespeare's comedy “A Midsummer Night's Dream” during a flower festival in Pakruojis, Lithuania on August 14, 2021. (Photo by Ints Kalnins/Reuters)

Dublin Horse Show mascot “Conor the Capall” among the crowds on the opening day of the 147th Dublin Horse Show at the RDS on Wednesday, August 17, 2022, the first to be held since 2019. The event which was first held in 1864 takes place over the next five days and includes national and international show jumping competitions. (Photo by Brian Lawless/PA Images via Getty Images)

The Cobra JoyRide car charger by Cobra Electronics is displayed during a press event at The Venetian for the 2012 International Consumer Electronics Show (CES) January 8, 2012 in Las Vegas, Nevada. The JoyRide works with Android phones and can automatically trigger preset phone functions like enabling GPS or disabling Wi-Fi with the press of a single button. It will be available for USD 39 in the second quarter of 2012. (Photo by Ethan Miller/Getty Images)

In this Saturday, March 3, 2018, photo, a contestant gets ready to throw a hatchet at a wooden bull's-eye at the Kick Axe Throwing venue in the Brooklyn borough of New York. Kick Axe Throwing is the first bar in New York City to pick up on a nationwide trend of ax throwing, a growing sport that some enthusiasts hope will take off the way bowling did in the last century. (Photo by Mary Altaffer/AP Photo)

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.