16-year-old panda, Ye Ye, rests in an enclosure at the Wolong Nature Reserve, a conservation center that trains pandas for release into the wild. This image was published in the August 2016 National Geographic magazine as part of the “Pandas Gone Wild” story. (Photo by Ami Vitale/National Geographic Creative)

A person takes part in the annual LGBTQ+ Pride parade in Phuket, Thailand on June 4, 2023. (Photo by Jorge Silva/Reuters)

This handout picture provided by the Saudi Media Ministry on April 24, 2023 shows a member of the Saudi Navy Forces carrying an evacuee baby upon arrival at King Faisal navy base in Jeddah, following a rescue operation from Sudan. Elderly women in wheelchairs and babies asleep in their parents' arms were among nearly 200 people from 14 countries who disembarked from a naval frigate in the coastal city of Jeddah on Monday night after daring – and draining – journeys to safety. (Photo by SPA/AFP Photo)

Children enjoy and participate in a traditional street race of “carruchas”, the name for makeshift wooden cars in Caracas, Venezuela, Saturday, December 18, 2021. Children enjoyed the race marking 10 years of persevering this tradition. (Photo by Ariana Cubillos/AP Photo)

Base jumpers leap from the 300-metre high skydeck of Malaysia's landmark Kuala Lumpur Tower against the backdrop of the city's skyline on October 3, 2016 during the annual International KL Tower Base-Jump event. (Photo by Manan Vatsyayana/AFP Photo)

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.

Indian School children's in a traditational attire of a characters of Indian epic Ramayan, on the eve of children's day celebration at cubbon park, in Bangalore, India, 13 November 2016. Children's day (also known as Bal Divas), in India is celebrated every year on 14th of November to increase the awareness of people towards the rights, care, and education of children. Many schools hold activities and allow students to have fun and attend their classes in coloured dresses. (Photo by Jagadeesh N.V./EPA)

A villager pours pesticide from a bucket as Mount Sinabung spews ash at Kebayaken village in Karo district, Indonesia's North Sumatra province, on December 4, 2013. The country has ordered the evacuation of 15,000 residents near the active volcano. (Photo by Roni Bintang/Reuters)