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.

Miniscule larvae carve winding tunnels as they eat through small leaves in a small forest near the town of Velbert in western Germany in July 2022. The hungry green sawfly larvae measure just three millimetres in length and are difficult to spot on the leaves of the beech tree unless up close. (Photo by Christian Brockes/Solent News)

A serviceman of the Carpathian Sich Battalion is seen at his position on a frontline, as Russia's attack on Ukraine continues, near the town of Lyman, Donetsk region, Ukraine on December 8, 2022. (Photo by Viacheslav Ratynskyi/Reuters)

Two storks sit in their nest as the sun rises in Wehrheim near Frankfurt, Germany, Thursday, August 29, 2024. (Photo by Michael Probst/AP Photo)

Revellers brave the rain as they make the most of New Year's Eve in Liverpool city centre, UK on December 31, 2024. (Photo by Ioannis Alexopoulos/London News Pictures)

A sharia executor, know as algojo, during a public caning punishment in Jantho, Aceh Besar Regency, Indonesia, 17 November 2017. Ten people were sentenced to public caning for adultery in Aceh, the only province in Indonesia which implements sharia law. (Photo by Hotli Simanjuntak/EPA/EFE)

In this photo released by Xinhua News Agency, a passenger jet that veered off a runway during take-off and caught fire is seen in the aftermath in Chongqing Jiangbei International Airport in southwestern China's Chongqing Thursday, May 12, 2022. The Chinese passenger jet left the runway upon takeoff and caught fire in western China on Thursday morning, and several people were injured. (Photo by Liu Chan/Xinhua via AP Photo)

In this photo released by Xinhua News Agency, a worker drinks at the construction site of the T3B terminal project of Chongqing Jiangbei International Airport in southwest China's Chongqing, July 11, 2022. Flooding and extreme high temperatures have caused multiple deaths in eastern China as summer heat descends earlier than usual. (Photo by Huang Wei/Xinhua via AP Photo)