A woman walks between Christmas trees at a Christmas market opened prior to incoming Christmas and New Year festivities in St. Petersburg, Russia, Friday, December 15, 2023. (Photo by Dmitri Lovetsky/AP Photo)

A dog walks on the street as it snows in Kyoto on January 25, 2024. (Photo by Philip Fong/AFP Photo)

Canada's Jean-Simon Desgagnes competes in the men's 3000m steeplechase final of the Pan American Games Santiago 2023 at the National Stadium in Santiago, on November 4, 2023. (Photo by Martin Bernetti/AFP Photo)

Bujang, a 35-year-old male orangutan rescued from a circus in Sumatra, washes his face on a sanctuary island surrounded by a river where non-releasable orangutans are protected for life at the Samboja Lestari Orangutan Rehabilitation Center run by the non-profit Borneo Orangutan Survival (BOS) Foundation in Samboja, East Kalimantan, on July 12, 2024. (Photo by Yasuyoshi Chiba/AFP Photo)

Nasoin Akhter, 15, has her makeup done at a beauty parlor on the day of her wedding to a 32-year-old man, August 20, 2015, in Manikganj, Bangladesh. In June of this year, Human Rights Watch released a damning report about child marriage in Bangladesh. The country has one of the highest rates of child marriage in the world, with 29% of girls marrying before the age of 15, and 65% of girls marrying before they turn 18. (Photo by Allison Joyce/Getty Images)

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.

Gertrude “Billie” Murphy, 22, is brought in for questioning in the murder case of Michael Stopec, who was shot and killed in an apartment hotel, circa July 1927. Murphy had been friends of the married Stopec and his suspected killer Henry Guardino, 31. It is said that Stopec and Guardino were “bitter rivals for the favor of Billie” and that Murphy had tired of Guardino and was going to stay with Stopec. Murphy was also married to a man in the Joliet penitentiary. (Photo by Chicago Herald & Examiner Historical Photo)

A Lion-Tailed macaque holds a big block of ice with a mix of frozen vegetables and fruit at the zoo in Leipzig, central Germany, Friday, July 19, 2013. Weather forecasts predict sunny weather and warm temperatures for Germany in the next few days. (Photo by Jens Meyer/AP Photo)