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.

Ariana Grande performs at Z100's Jingle Ball in Manhattan, New York, U.S., December 9, 2016. (Photo by Andrew Kelly/Reuters)

A production department of a textile factory is seen abandoned in Kaduna, Nigeria November 3, 2016. President Muhammadu Buhari hopes to revive the once flourishing textile and leather industries in northern Nigeria to end the country's dependence on oil exports and diversify Africa's biggest economy. (Photo by Afolabi Sotunde/Reuters)

Randy Orton is seen in action against Rey Mysterio during the single match of WWE “Crown Jewel” World Cup 2018 tournament at King Saud University stadium in Riyadh, Saudi Arabia on November 2, 2018. (Photo by Faisal al Nasser/Reuters)

A photojournalist is silhouetted by the sunset as a lightning strike at a resort affected by Saturday's tsunami in Carita, Indonesia, Tuesday, December 25, 2018. Christmas celebrations traditionally filled with laughter and uplifting music were replaced by somber prayers for tsunami victims in an area hit without warning following a volcanic eruption, leaving hundreds of people dead and thousands homeless in disaster-prone Indonesia. (Photo by Fauzy Chaniago/AP Photo)

A Hindu devotee prepares for Annakut or Goverdhan puja at Naba Brindaban temple in Kolkata on November 14, 2023. Annakut or Govardhan Puja is a Hindu festival in which devotees prepare and offer a large variety of vegetarian food to Lord Krishna as a sign of gratitude for saving them from floods as per Hindu Mythology. (Photo by Avishek Das/SOPA Images/Rex Features/Shutterstock)

Members of the Hitler Youth who are trained to report airstrikes repaining their bicycles. Published by: “Die Sirene”. 1942. (Photo by Herbert Hoffmann/Ullstein Bild via Getty Images)

The civilised world lies on its knees, a sickness wracking its body. The affliction causes a necrotising of tissues so perfectly uniform in distribution that victims take on the appearance of corpses long before death occurs due to organ failure or secondary infections. ...