Believers bathe in the icy water during a traditional Epiphany at the Church of the Holy Trinity in Ostankino near TV Tower in Moscow, Russia, Wednesday, January 18, 2023. Across Russia, the devout and the daring are observing the Orthodox Christian feast day of Epiphany by immersing themselves in frigid water through holes cut through the ice of lakes and rivers. Epiphany celebrates the revelation of Jesus Christ as the incarnation of God through his baptism in the River Jordan. (Photo by Alexander Zemlianichenko/AP Photo)

Participants jump into the water during the 114th edition of the Copa Nadal (Christmas Cup) swimming race in Barcelona's Port Vell on December 25, 2023. The traditional 200-meter Christmas swimming race gathered around 300 participants on Barcelona's Port Vell (old harbour). (Photo by Josep Lago/AFP Photo)

Shortlist, open competition, lifestyle. Healing Vibes – the hot springs of Bagno Vignoni in Italy flow out at a temperature of about 49°C. They were appreciated by the Romans for their healing powers, and have been used as therapeutic treatments since the 12th century, under Emperor Federico II. (Photo by Stefano Butturini/Sony World Photography Awards)

In this Thursday, May 25, 2017 photo, Donte, a musician who only gave his first name, straightens out dollar bills on his first day in a brand new Chewbacca costume purchased from eBay for $441, in the Hollywood section of Los Angeles. Donte said he replaced the old one because he wasn't making any money with it. (Photo by Jae C. Hong/AP Photo)

Miniature spring-wound 35-mm film camera in a modified cigarette pack. The Tessina’s small size and quiet operation provided more options for concealment than most commercially available models. (Photo by Central Intelligence Agency)

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 man takes a photo of a radio antenna that's part of the Atacama Large Milimeter Array Observatory on March 12, 2013 at Llano de Chajnantor, about 43 miles (70 kilometers) from San Pedro de Atacama, Chile. The $1.5 billion ALMA facility, which had its official inauguration on March 13, is considered the world's most expensive ground-based observatory. (Photo by Felipe Trueba/EPA)

The new EVR system which allows the recording of television programmes which can then be watched at the owner's discretion. The new Teleplayer has been produced in partnership with Rank Bush Murphy Ltd and EVR and has enormous potential. 21st September 1970. (Photo by Central Press/Getty Images)