Afghan dogs fight during the weekly dog fight in Kabul, Afghanistan, 17 February 2017. Under the Taliban dog fighting was forbidden, but since their fall it has become a major source of entertainment for hundreds of Afghans, where bets can amount to thousands of dollars and the dogs, which must be over one year old, are well-cared for by their owners and fed milk, butter and meat. (Photo by Hedayatullah Amid/EPA)

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 young Afghan vendor waits for customers to buy sheep's heads at a roadside stall at the busy market in Kabul on November 29, 2015. (Photo by Wakil Kohsar/AFP Photo)

Revellers take part in the annual block party known as “Casa Comigo” (Marry Me), during carnival festivities in Sao Paulo, Brazil on February 15, 2020. (Photo by Rahel Patrasso/Reuters)

A view of the start of the 37th Gotland Grand National motocross race in Visby, Sweden on October 24, 2020. (Photo by Soren Andersson/TT News Agency via Reuters)

The DFDS King of seaways enters the Mouth of the Tyne on the North East coast in Rough sea on Wednesday, January 18, 2023. (Photo by Owen Humphreys/PA Images via Getty Images)

Manar Abu Dhabi presents its second public light art exhibition on November 17, 2025. Organized by the Department of Culture and Tourism. KAWS, located at Souq Al Mina, Abu Dhabi. (Photo by Victor Besa/The National)

Revelers dance at a Jacarezinho samba school practice session ahead of Carnival celebrations on February 16, 2014 in Rio de Janeiro, Brazil. The Jacarezinho “favela” was previously controlled by drug traffickers and is now occupied by the city's Police Pacification Unit (UPP). Carnival officially begins February 28, but pre-Carnival celebrations are already underway. (Photo by Mario Tama/Getty Images)