A rat's head rests as it is constricted in an opening in the bottom of a garbage can in the Brooklyn borough of New York, U.S., October 18, 2016. The Brooklyn rat was saved on Tuesday after getting its head stuck in the dumpster while scavenging for food, according to the New York Daily News. As the rat was scurrying around the bottom of the trash can, it came across a few ventilation holes. The hungry creature poked his head into one of them, but to its dismay couldn't get back out,Reuters photographer Lucas Jackson told the Daily News. Jackson was able to take some adorable photos of the rat's unfortunate situation before it was rescued. (Photo by Lucas Jackson/Reuters)

Kim Kardashian looks to have left her underwear at home as she heads out for an early dinner with boyfriend Kanye West in Miami on October 14, 2012. As Kim checked out her outfit in the reflection of her car, it became apparent that the reality star was not wearing any underwear as she showed off her see-through grey skirt. (Photo by Brett Kaffee/Thibault Monnier/PacificCoastNews.com)

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.

Lady Gaga performs on ABC's “Good Morning America” at Rumsey Playfield, Central Park on May 27, 2011 in New York, United States. (Photo by Andrew H. Walker/Getty Images)

Just a week before Rio de Janeiro hosts South America's first Olympics, city residents expressed mixed feelings about the cost and security of the Games, while holding out hope they will bring joy to a nation facing economic and political crises. The conflicted thoughts mirror a recent survey by the Datafolha polling group showing that half of Brazilians were opposed to holding the Games, while 63 percent think the costs of hosting the event will outweigh benefits. (Photo by Pilar Olivares/Reuters)

Chrisitan pilgrims carry wooden crosses along the Via Dolorosa during the Good Friday procession on April 22, 2011 in Jerusalem, Israel. Thousands of Christians around the world will today mark Good Fiday when they commemorate the crucifixion of Jesus Christ. In Jerusalem Christian pilgrims took part in processions along the route that Jesus is believed to have taken in his last days as he carried the cross. (Photo by Uriel Sinai/Getty Images)

Bat seller Sukarwati shows a skinned bat on July 30, 2009 in Yogyakarta, Indonesia. Sukarwati and her family have hunted bats in the Imogiri region for generations, capturing more than 800 bats per month. The Sukarwati family believe that the meat from the bat heals asthma and respiratory problems and it is a great honour for them knowing that the meat that they provide will help ease people's health ailments. (Photo by Ulet Ifansasti)

Candice Swanepoel attends the Victoria's Secret Very s*xy Tour Stop in Dallas at Victoria's Secret Beauty at the NorthPark Mall on March 22, 2012 in Dallas, Texas. (Photo by Peter Larsen/ Getty Images for Victoria's Secret)