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.

“Magician David Blaine's latest stunt boasts lots of high-voltage snap, crackle and pop – but experts say he'll be safe from electrocution as long as he wears his chain-mail suit and metal headgear”. – NBC News. Photo: Blaine stands inside the apparatus, surrounded by a million volts of electric currents streamed by tesla coils. The stunt, sponsored by Intel, is the latest of daredevil endeavors by the magician whose previous stunts included being encased in ice for over 60 hours in Times Square, on October 5, 2012. (Photo by John Minchillo/Associated Press)

“A skydiver has made history by smashing the world record for the highest skydive after leaping from 128,097ft (39,044m). Daredevil Felix Baumgartner ascended to the edge of space in a pressurised capsule suspended beneath a giant helium balloon. He then jumped out, freefalling for four minutes and 19 seconds before opening his parachute”.

Photo: Baumgartner celebrates after successfully completing the jump. (Photo by Balazs Gardi/Red Bull Stratos)

Kourtney Roy makes eerie self-portraits in desolate yet dramatic locations – with wigs and wardrobe straight out of 1950s melodrama. In these shots, from her “Enter as Fiction – California” series, she plays characters caught in desolate, often abandoned settings. (Photo by Kourtney Roy/Galerie Catherine et André Hug/The Guardian)

Ghanaian fans take a selfie prior to a Group G football match between Germany and Ghana at the Castelao Stadium in Fortaleza during the 2014 FIFA World Cup on June 21, 2014. (Photo by Patrik Stollarz/AFP Photo)

Talk-show host Oprah Winfrey interviewing cyclist Lance Armstrong during taping for the show "Oprah and Lance Armstrong: The Worldwide Exclusive" in Austin, Texas. The two-part episode of "Oprah's Next Chapter" will air nationally Thursday and Friday, Jan. 17-18, 2013. (AP Photo/Courtesy of Harpo Studios, Inc., George Burns)

A fan of Serbia scuffles with Albania's Mergim Mavraj during their Euro 2016 Group I qualifying soccer match at the FK Partizan stadium in Belgrade October 14, 2014. The Euro 2016 qualifier between Serbia and Albania was abandoned on Tuesday following a brawl between players from both sides. (Photo by Marko Djurica/Reuters)

General view of a clash after the match of the Egyptian Premier League between Pyramids FC and Zamalek at the 30 June Air Defense Stadium in Cairo, Egypt on April 23, 2019. (Photo by Amr Abdallah Dalsh/Reuters)