Burmese monks take their yearly exam December 13, 2011 in Bago, Myanmar. Around 1,400 monks from Bago province took part . (Photo by Paula Bronstein /Getty Images)

A herd of wild monkeys ask for food from passing vehicles along a mountain road after a snowfall on October 20, 2020 in Luhuo County, Sichuan Province of China. (Photo by Jin Shujie/VCG via Getty Images)

Geology Professor Fetullah Arik takes measurements next to a large sinkhole on June 03, 2021, in Karapinar, Turkey. In Turkey’s Konya province, the heart of the country's agriculture sector, extreme drought conditions over the past two years are taking a heavy toll on farmers and the land. (Photo by Chris McGrath/Getty Images)

A kingfisher dives into the leafy water of the River Alde near Rendham, Suffolk in the second decade of November 2022 and catches two fish. Kingfishers must be able to see the fish they want to catch before making their dive, so for this bird to be successful when leaves covered the surface of the water shows its true skill for survival. (Photo by Ivor Ottley/Animal News Agency)

A black-winged stilt patrols a reservoir in Jezreel Valley in Israel early April 2023. Their eggs are a golden colour mottled with brown. (Photo by Itamar Procaccia/Solent News)

Demonstrators who blocked a main road with their vehicle to demand fuel near President Gotabaya Rajapaksa's residence, argue with a police officer, during the country's economic crisis, in Colombo, Sri Lanka on June 29, 2022. (Photo by Dinuka Liyanawatte/Reuters)

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.

This picture taken on May 24, 2019 shows Mariam the dugong as she is cared for by park officials and veterinarians from the Phuket Marine Biological Centre on Libong island, Trang province in southern Thailand. An orphaned baby dugong rescued off a beach in Krabi province is Thailand's newest star, capturing the hearts of millions on social media and igniting an awarness for ocean conservation as authorities hand-raise the young mammal. (Photo by Sirachai Sirachai Arunrugstichai/AFP Photo)