Russian Tu-95MS strategic bombers fly in formation during rehearsals for the Victory Day military parade, with St. Basil's Cathedral seen in the foreground, in central Moscow May 5, 2015. Russia will celebrate the 70th anniversary of the victory over Nazi Germany in World War Two on May 9. (Photo by Tatyana Makeyeva/Reuters)

A model prepares backstage during the body painting show : Miracle World The Ocean organized by Unipa Surabaya at Grand Atrium Royal Plaza on June 21, 2021 in Surabaya, Indonesia. (Photo by Robertus Pudyanto/Getty Images)

The new MacBook Pro is shown during the keynote address at the Apple 2012 World Wide Developers Conference (WWDC) at Moscone West on June 11, 2012 in San Francisco, California. This is Apple’s latest flagship laptop featuring an updated processor and a super high resolution screen that features 5.1 million pixels – 3 million more than a typical high-definition television.

A member of the Philippine National Police stands guard as he detains people as part of the “Rid the Streets Of Drinkers and Youth” operation on a main road in Las Pinas city, metro Manila, Philippines June 1, 2016. (Photo by Romeo Ranoco/Reuters)

An injured protestor is led away during clashes with police near Tahrir Square on November 23, 2011 in Cairo, Egypt. Thousands of Egyptians are continuing to occupy Tahrir Square after four days of clashes with security forces despite a promise from military leaders to bring forward Presidential elections. (Photo by Peter Macdiarmid/Getty Images)

A farmer uses a GoPro as he takes a picture of his carabao kneeling during the annual Carabao Festival in Pulilan, Bulacan in northern Philippines May 14, 2015. Water buffalos, locally known as carabaos, are led during a parade in the streets of the town to honour its patron saint San isidro Labrador, and carabaos will kneel in front of the church to give thanks for a year-long bountiful harvest. (Photo by Lorgina Minguito/Reuters)

A blurred panaroma of Roemerberg historic center is reflected in a soap bubble in Frankfurt am Main, Germany, 09 July 2015. (Photo by Frank Rumpenhorst/EPA)

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.