A model presents a creation by Japanese designer Yoshikazu Yamagata for his label writtenafterwards during the Mercedes-Benz Fashion Week in Tokyo, Japan, 16 March 2016. The presentation of the Autumn/Winter 2016 collections runs from 14 to 19 March. (Photo by Kiyoshi Ota/EPA)

Popocatepetl volcano spews incandescent material as seen from Paso de Cortés on May 23, 2023 in Amecameca, Mexico. The second highest volcano in the country increased its activity while Mexican authorities raised the alert to yellow phase 3. Popocatepetl volcano caused the fall of ashes in different municipalities in Puebla, Estado de Mexico and Mexico City. Mexican army has spread forces as a preventive measure while the 3 levels of government are in coordination to observe the activity of the volcano and the situation in the surroundings. (Photo by Cristopher Rogel Blanquet/Getty Images)

Maj. Matt O'Donnell of Glenelg, MD shields himself from rotor wash as Ospreys carrying the delegation of U.S. Secretary of Defense Leon Panetta leaves on March 14, 2012 at Forward Operating Base Shukvani, Afghanistan. Panetta is also scheduled to meet with President Karzai during his two-day visit to Afghanistan. The trip comes as the Taliban has vowed revenge following this past weekend's killing spree by a U.S. soldier who is accused of killing 16 civilians in Afghanistan. Most of those killed were children and women. (Photo by Scott Olson/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.

Gold bars from the vault of a bank and Swiss one franc coins are seen in this illustration picture taken in Zurich November 20, 2014. The “Save our Swiss gold” proposal, spearheaded by the right-wing Swiss People's Party (SVP), aims to ban the central bank from offloading its reserves and oblige it to hold at least 20 percent of its assets in gold. The referendum is scheduled for November 30. The SVP argues it would secure a stable Swiss franc. (Photo by Arnd Wiegmann/Reuters)

(From L) Spanish actresses Aixa Villagran, Leticia Dolera and Celia Freijeiro pose on the pink carpet during the closing night of the 2019 Cannes International Series festival Canneseries, at the Palais des festival, in Cannes southern France, on April 10, 2019. (Photo by Valéry Hache/AFP Photo)

One of the most significant challenges related to cancer in Nepal is the lack of awareness around the prognosis of the disease, as many patients, their families and even healthcare professionals consider cancer to be an incurable disease at any stage. This results in significant delays in bringing patients to hospitals, and high rates of advanced stage cancers and mortality. (Photo by Omar Havana)

In this January 27, 2020 photo, Jessica Hahn-Chaplin applies make up before a rehearsal of the Paraiso de Tuiuti samba school in Rio de Janeiro, Brazil. Hahn-Chaplin dances samba annually in Bath, England. (Photo by Silvia Izquierdo/AP Photo)