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.

A Naga sadhu, or naked Hindu holy man, performs a ritual inside his tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Friday, August 28, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Rajanish Kakade/AP Photo)

Hirari Ikeda, a well-known Harajuku street fashion personality, on the street in Shibuya. (Photo by Tokyo Fashion)

Nigerian fashion models are made up for their fashion show to promote ethnic fashion June 13, 2006 in Tel Aviv, Israel. The models said they hope to use the travelling show as a springboard to international fame, in the words of one, “to be the next Naomi Campbell”. (Photo by Uriel Sinai/Getty Images)

Sabrina Crespo da Silva removes electrical tape from a client at her Sabrina Bronze rooftop salon, where she offers the service of taping on bikini tops which create crisp tan lines, in the Turano favela of Rio de Janeiro, Brazil, Thursday, January 27, 2022. Even though beaches reopened amid the COVID-19 pandemic, some clients using Sabrina's rooftop service say they are still anxious about returning to the crowded seashore and potentially catching the virus. (Photo by Silvia Izquierdo/AP Photo)

Natalie Geisenberger of Germany, Johannes Ludwig of Germany, Tobias Wendl of Germany and Tobias Arlt of Germany celebrate their teammates slide winning gold during the Luge Team Relay on day six of the Beijing 2022 Winter Olympics at National Sliding Centre on February 10, 2022 in Yanqing, China. (Photo by Thomas Peter/Reuters)

Ukraine's Olga Polyuk falls while competing in the freestyle skiing women's aerials qualification during the Beijing 2022 Winter Olympic Games at the Genting Snow Park A & M Stadium in Zhangjiakou on February 14, 2022. (Photo by Marco Bertorello/AFP Photo)