In this October 6, 2018, photo, a craftsman makes daggers or “Jambiyya” in Yemeni Arabic, made out of remains of missiles, at his workshop, in Hajjah, Yemen. Missiles raining on Yemen from the jets of the Saudi-led coalition fighting Houthi rebels are killing thousands of civilians and militiamen alike, but amid crashing economy, some Yemenis see the bright side of it: they make daggers out of the fragments of the missiles for ordinary men traditionally wear for prestige and a show of courage. (Photo by Hammadi Issa/AP Photo)

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.

An Indonesian model wearing a colorful costume participates in a parade during the Batam Island International Culture Festival in Batam Island, Indonesia, 16 December 2017. Batam Island, an industrial area in Indonesia, is boosting the tourism sector to improve the economy of its community by eyeing the visitors' boom of next door country Singapore. (Photo by Hotli Simanjuntak/EPA/EFE)

Workers carry sacks of coffee beans at a warehouse at the Nogales farm in Jinotega, Nicaragua January 7, 2016. Soaring temperatures in Central America due to climate change are forcing farmers to pull up coffee trees and replace them with cocoa, spurring a revival in the cultivation of a crop once so essential to the region's economy. (Photo by Oswaldo Rivas/Reuters)

In this file photo taken on Sunday, August 2, 2020, Sviatlana Tsikhanouskaya, candidate for the presidential elections greets people waving old Belarus flags during a meeting to show her support, in Brest, 326 km (203,7 miles) southwest of Minsk, Belarus. Belarus’ authoritarian President Alexander Lukashenko faces a perfect storm as he seeks a sixth term in the election held Sunday, Aug. 9, 2020 after 26 years in office. Mounting public discontent over the worsening economy and his government’s bungled handling of the coronavirus pandemic has fueled the largest opposition rallies since the Soviet collapse. (Photo by Sergei Grits/AP Photo)

A Baby sumatran orangutan (Pongo abelii) plays around in a tree as they train at Sumatran Orangutan Conservation Programme's rehabilitation center on November 12, 2016 in Kuta Mbelin, North Sumatra, Indonesia. The Orangutans in Indonesia have been known to be on the verge of extinction as a result of deforestation and poaching. Found mostly in South-East Asia, where they live on the islands of Sumatra and Borneo, the endangered species continue to lose their habitat as a result of corporate expansion in a developing economy. Indonesia approved palm oil concessions on nearly 15 million acres of peatlands over the past years and thousands of square miles have been cleared for plantations, including the lowland areas that are the prime habitat for orangutans. (Photo by Ulet Ifansasti/Getty Images)

A mechanic examines a Gogoro Smartscooter which is connected to a tablet, in its shop in Taipei, Taiwan, July 6, 2015. Companies such as electric motor scooter firm Gogoro could hold the key to Taiwan's economic growth. In just three years, the start-up raised $150 million to develop the smartphone-synched bike, and a charging network for it. Gogoro's success in creating a home-grown, innovative product is precisely what Taiwan's government wants to foster as it seeks to reduce the export-driven economy's reliance on the island's world-class tech manufacturing sector. (Photo by Pichi Chuang/Reuters)

A drone operated by paramilitary police flies over the site of last week's explosions at Binhai new district in Tianjin, China, August 17, 2015. Many operations have resumed at China's Tianjin port, trade sources said, after explosions last week that killed more than 100 people and disrupted business at what is an important oil, gas and bulk import harbor for Asia's biggest economy. The explosions on August 12 led to the disruption of all chemical and oil tanker discharges at the port, and imports of iron ore were also affected. (Photo by Kim Kyung-Hoon/Reuters)