Several beaches along South Florida's Atlantic coast line were closed after thousands of sharks were seen migrating in the waters. The sharks were migrating from Boca Raton to Jupiter since the beginning of March, marine biologists told NBC Miami. Photo: A spinner shark swims just offshore on Midtown Beach in Palm Beach on Tuesday. (Photo by Jeffrey Langlois/Palm Beach Daily News)

Armed Syrian Turkmen villagers are seen near the northern Syrian village of Yamadi, near the Turkish-Syrian border, Syria, November 24, 2015. Turkey shot down a Russian warplane near the Syrian border on Tuesday saying it had repeatedly violated its air space, one of the most serious publicly acknowledged clashes between a NATO member country and Russia for half a century. (Photo by Reuters/Stringer)

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.

In this January 23, 2021, file photo, a police officer detains a young woman during a protest against the jailing of opposition leader Alexei Navalny in Pushkin square in Moscow, Russia. Allies of Navalny are calling for new protests next weekend to demand his release, following a wave of demonstrations across the country that brought out tens of thousands in a defiant challenge to President Vladimir Putin. (Photo by Alexander Zemlianichenko/AP Photo/File)

Family members pose for photos near lava flowing from Pacaya Volcano near El Patrocinio village in San Vicente Pacaya, Guatemala, Friday, April 16, 2021. (Photo by Moises Castillo/AP Photo)

The Duchess of Cambridge comes down a slide during a visit to the LEGO Foundation PlayLab at the Carlsberg Campus, University College Copenhagen, Denmark, on day one of a two-day working visit with The Royal Foundation Centre for Early Childhood on Tuesday, February 22, 2022. (Photo by John Sibley/PA Wire Press Association)

A person makes faces as they march in the Societe de Sainte Anne parade during Mardi Gras on Tuesday, March 1, 2022, in New Orleans. (Photo by Gerald Herbert/AP Photo)

A woman daubed in colours shakes her head to remove the coloured powder during Holi celebrations in Ahmedabad, India on March 18, 2022. (Photo by Amit Dave/Reuters)