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.

Lizzy Huggler, 20 ,wears blue ties on her legs on the third day of the Firefly Music Festival in Dover, Delaware U.S., June 16, 2018. (Photo by Mark Makela/Reuters)

Ava Max poses with the Best Push award at the backstage during the 2019 MTV Europe Music Awards at the FIBES Conference and Exhibition Centre in Seville, Spain, November 3, 2019. (Photo by Jon Nazca/Reuters)

Fireworks from Japan light up the sky at the start of the 6th Pyro musical competition Saturday, February 7, 2015 at the Mall of Asia shopping complex at suburban Pasay city south of Manila, Philippines. The fireworks competition, which runs for six consecutive weekends, features entries from 11 countries as host country the Philippines, Canada, United States, Japan, United Kingdom, Brazil, Portugal, China, Mexico, Italy, The Netherlands and Sweden, with Canada winning the championship last year. (Photo by Bullit Marquez/AP Photo)

Jennifer Lopez, left, is embraced by Pitbull at the end of her performance at the 42nd annual American Music Awards at Nokia Theatre L.A. Live on Sunday, November 23, 2014, in Los Angeles. (Photo by Matt Sayles/Invision/AP Photo)

Dinah Jane, from left, Normani Kordei, Lauren Jauregui, and Ally Brooke of Fifth Harmony perform a medley at the MTV Video Music Awards at The Forum on Sunday, August 27, 2017, in Inglewood, Calif. (Photo by Chris Pizzello/Invision/AP Photo)

People in traditional dance before competing in the 53rd Verdiales music contest in Malaga, southern Spain December 28, 2014. Verdiales is a form of traditional Flamenco music, which is common in the province of Malaga. Members of singing groups, known as “pandas”, wear traditional costumes decked with flowers and other accessories as they perform in the contest, which is held annually on December 28. (Photo by Jon Nazca/Reuters)

Julya Baer, 30, attends a candlelight vigil and celebration of Prince's life in Leimert Park in memory of musician Prince on April 21, 2016, in Los Angeles, California. Prince died earlier today at his Paisley Park compound at the age of 57. (Photo by Kevork Djansezian/Getty Images)