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 volunteer photographs a woman as she kisses a volunteer wearing a condom costume during marking the International Condom Day in Kiev, Ukraine, 13 February 2015. The event was organized to promote and create awareness towards “Safe s*x” and the use of condoms to control and prevent Human Immunodeficiency Virus (HIV) and other sexually transmitted diseases on the occasion of the International Condom day. (Photo by Roman Pilipey/EPA)

Bomarzo's main attraction is a garden, usually referred to as the Bosco Sacro (Sacred grove) or, locally, Bosco dei Mostri ("Monsters' Grove"), named after the many larger-than-life sculptures, some sculpted in the bedrock, which populate this predominantly barren landscape.

“Attacking Howler Monkey”. Due to a major tropical rainstorm my wife and I were forced to stay overnight in a Howler Monkey Rescue center in Panama. I used the time to explore the area and to take photos of the monkeys. Just after the rain finally stopped, I ran into this monkey that tried to mock attack me. I quickly took a couple of photos before retreating to a (more) safe distance. (Photo and caption by Christian Mueller-Planitz/National Geographic Traveler Photo Contest)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

“Miniatur Wunderland is a model railway attraction in Hamburg, Germany and the largest of its kind in the world. As of January 2011, the railway consists of 12,000 metres (39,370 ft) of track in HO scale, divided into seven sections: Harz, the fictitious city of Knuffingen, the Alps and Austria, Hamburg, America, Scandinavia, and Switzerland. Of the 6,400 square metres (68,889 sq ft) of floorspace, the model takes 1,150 m2 (12,378 sq ft)”. – Wikipedia

Photo: Details of the “Miniatur Wunderland” are pictured on April 2, 2009 in Hamburg, Germany. The world's largest model railway and one of the most popular tourist attractions in Germany is located next to the Elbe in Hamburg's Speicherstadt. (Photo by Joern Pollex/Getty Images)

The Cobra JoyRide car charger by Cobra Electronics is displayed during a press event at The Venetian for the 2012 International Consumer Electronics Show (CES) January 8, 2012 in Las Vegas, Nevada. The JoyRide works with Android phones and can automatically trigger preset phone functions like enabling GPS or disabling Wi-Fi with the press of a single button. It will be available for USD 39 in the second quarter of 2012. (Photo by Ethan Miller/Getty Images)

A tourist crosses flooded St. Mark's Square in Venice, Italy on November 11, 2012. Flooding is common this time of year and Sunday's level that reached a peak of 58.66 inches was below the 63 inches recorded four years ago in the worst flooding in decades. (Photo by Luigi Costantini/Associated Press)

These heartwarming images capture the pure happiness of young children playing with a buffalo in the sweltering Indonesian heat on July 28, 2018. The children are all sons of the farmers who work on the rice farms in the West Java region of Indonesia. Amateur photographer Tamlikho Tam, 46 from Depok in West Java Indonesia snapped up the joyful moment because it shows what a typical childhood should be like without technology. (Photo by Tamlikho Tam/South West News Service)