A woman walks up a stairway painted in the rainbow colors in Bucharest, Romania, Saturday, July 11, 2020. Romania reported 698 new COVID-19 infections in the last 24 hours, the highest level since the pandemic reached the country in February. (Photo by Vadim Ghirda/AP Photo)

Students on their way home from school play in a river which has risen due to recent seasonal rains, in a remote village in Panca, Aceh province on January 22, 2021. (Photo by Chaideer Mahyuddin/AFP Photo)

A hot air balloon in tortoise shape flies in the air during the Tazaungdaing air balloon festival in Pyin Oo Lwin, Myanmar, 25 November 2015. During the festival, hot air balloons made of multicolored papers and hung with paper lanterns, fireworks and fire sticks are exploded in mid-air. (Photo by Hein Htet/EPA)

“Coming back home at 5am sunrise, I was just beginning to digest the grand event I was lucky to witness and cover: the wedding of the grandson of one of the most influential spiritual leaders in Israel’s ultra-Orthodox community...”. – Ronen Zvulun via Reuters. Photo: Ultra-orthodox Jewish wedding in Israel. Tens of thousands of Ultra-Orthodox Jews of the Belz Hasidic dynasty gather at the wedding ceremony of Rabbi Shalom Rokach in Kiryat Belz, in Jerusalem, on May 21, 2013. Around 25,000 ultra-orthodox Jews took part, making it one of the biggest weddings of the past few years. (Photo by Gil Cohen)

A musician from the Rajan Band, Kotla Mubarakpur holds on to a decorated horse as he and others wait prior to performing at a wedding on November 22, 2011 in New Delhi, India. (Photo by Daniel Berehulak/Getty Images)

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.

Bolivian sеx workers sit during a Reuters interview before the countrywide, two-week mandatory quarantine to combat the spread of coronavirus disease (COVID-19), decreed by Bolivia's interim government, in El Alto outskirts of La Paz, Bolivia on March 20, 2020. (Photo by Monica Machicao/Reuters)

A grasshopper in a protective mask created by microminiaturist Anatoly Konenko in Omsk, Russia on May 21, 2020. Mini-masks about the size of a rice grain are made of a special high-density medical fabric with a built-in air filter. Anatoly Konenko is one of Russia's most famous microminiaturists; his works include a grasshopper playing a violin, a shod flea, a miniature bass guitar, a camel train in a needle's eye, and over 200 miniature books. (Photo by Yevgeny Sofiychuk/TASS)