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.

Pod of dolphins surf effortlessly through the waves in the wild traveling at speeds up to 20 mph. (Photo by Greg Huglin)

Inspired by traditional Indian travelling photography studios, Arthur Crestani photographed the inhabitants of Gurgaon, a city built almost entirely by private companies. Arthur Crestani’s “Bad City Dreams” contrasts the glossy ideal sold by developers with urban reality. Here: Luxury Living Bhiwadi: “Sky Club on 18th Floor”. (Photo by Arthur Crestani/The Guardian)

Members of the Gremlins Carnival Club, open the doors to their workshop to unveil for the first time their cart, Jungle Drums, which is their entry to this year's Bridgwater Carnival, on November 4, 2011 in Bridgwater, England. (Photo by Matt Cardy/Getty Images)

A group of sadhus (holy men) participate in a religious rally to mark the Mahashivaratri festival at Pashupati Temple in Kathmandu, Nepal, 06 March 2024. The festival celebrated on 08 March, sees Hindu devotees from across the country and neighboring India gather to fast and offer special prayers to celebrate the birthday of Lord Shiva, the Hindu god of creation and destruction. (Photo by Narendra Shrestha/EPA/EFE)

A woman wades through a flooded village in the eastern state of Bihar, India August 22, 2017. (Photo by Cathal McNaughton/Reuters)

A four-week old southern three-banded armadillo (Tolypeutes matacus) is rolled up into a ball next to its mother in the tropical house of Budapest Zoo in Budapest, Hungary on May 3, 2019. The South American insect-eating mammal and its close relative, the Brasilian three-banded armadillo (Tolypeutes tricinctus) are the only two species of armadillos capable of rolling into a complete ball to defend themselves when feeling threatened. (Photo by Attila Kovács/EPA/EFE)