Japan Agricultural Cooperation Kagawa employees arrange cubic watermelons to be shipped within the country, in Zentsuji city, Kagawa prefecture, western Japan, Wednesday, June 24, 2020. The about 18x18x18-centimeter (7x7x7-inch) square watermelons, grown in transparent square containers, will be sold for about 10,000 yen ($94) each. (Photo ny Maiko Hirai/Kyodo News via AP Photo)

A conscript hugs a girl as he says goodbye to family members at a local railway station during departure for the garrisons, in Sevastopol, Crimea on November 9, 2022. (Photo by Alexey Pavlishak/Reuters)

Students with torches protest against the alleged encroachment of Nepal border by India in far west of Nepal, during the 49th day of a lockdown imposed by the government amid concerns about the spread of the coronavirus disease (COVID-19), in Kathmandu, Nepal on May 11, 2020. (Photo by Navesh Chitrakar/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.

Members of the staff wait for the start of the maiden press conference for China's all-girl “boyband” FFC-Acrush in Beijing, China April 28, 2017. Picture taken April, 28, 2017. (Photo by Damir Sagolj/Reuters)

Police spraying protesters with pepper spray inside Central Station after a Black Lives Matter rally in Sydney, Australia, 06 June 2020, a protest against the deaths of Aboriginal people in custody and solidarity with the US protests for George Floyd. (Photo by James Gourley/EPA/EFE)

Smoke rises from a house days after part of the ground it was resting on collapsed into Lake Whitney, Texas in this June 13, 2014 file photo. I was covering the controlled burn of a house slowly falling into Lake Whitney due to the decaying cliff underneath. Asked to take photos from an aerial perspective, an instructor and I took off from Grand Prairie Municipal Airport around 9am. The burn, scheduled to start an hour later, was delayed. I love flying, but patience proved challenging as circling for nearly three hours gets boring fast. Once the fire started we only had 15 minutes to take photos because the plane was booked at 1pm. The owners invested their retirement savings in the house and were even advised by geologists that the ground was stable. To watch your investment literally go up in flames must take its toll emotionally. The owners said they don't expect their insurance to cover the loss. (Photo and caption by Brandon Wade/Reuters)

A general view showing the shipwrecked cruise ship Costa Concordia in an upright position after the salvage operations in Giglio island, Italy, 17 September 2013. Salvage crews pulled off a major engineering feat when they straightened the listed Costa Concordia cruise ship from the rocks it had been wedged against for the past 20 months. The delicate operation took 19 hours and was completed at 4 am (0200 GMT). The vessel ran aground near the island of Giglio, in Tuscany, in an accident that made world-wide news. (Photo by Angelo Carconi/EPA)