A United States Air Force (USAF) F-15 fighter jet travels at low altitude through the “Mach Loop” series of valleys near Dolgellau, north Wales on June 26, 2018. The Mach Loop valleys, situated between Dolgellau and Machynlleth, are regularly used by the military for operational low flying training which can take place as low as 76 metres from the nearest terrain. The USAF regularly use the loop to practice low-altitude flight, which confuses radar systems. (Photo by Oli Scarff/AFP Photo)

“A guide horse is an experimental mobility option for blind people who do not wish to or cannot use a guide dog. They are provided by The Guide Horse Foundation, founded in 1999 to provide miniature horses as assistance animals to blind users living in rural environments”. – Wikipedia

Photo: Shari Bernstiel, of Lansdale, Pennsylvania is helped along the sidewalk by Tonto, her guide horse March 19, 2004 in Lansdale, Pennsylvania. Tonto, a minature horse who went through one year of training, acts as Sheri's seeing eye dog and is one of three working guide horses in the United States. (Photo by William Thomas Cain/Getty Images)

Krastsvetmet, located beside the beautiful Yensei river in the metropolis of Krasnoyarsk, Russia, is a refinery of all types of precious metals on an industrial scale.

Owner Nicole Graham works with volunteers from CFA and SES tries to dig out her horse “Astro” who became stuck up to his neck in mud at Avalon Beach on February 26, 2012 in Geelong, Australia. The tide was fast-rising, but the rescuers managed to get him out in time. (Photo by Peter Ristevski/Newspix)

Traditional Hungarian horsemen pose as one of them cracks his whip over his horse in the Great Hungarian Plain in Hortobagy, Hungary June 30, 2016. (Photo by Laszlo Balogh/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.