Muslim girls are seen after prayers, in Lagos, Nigeria, Friday, July 31, 2020. Small groups of pilgrims performed one of the final rites of the Islamic hajj on Friday as Muslims worldwide marked the start of the Eid al-Adha holiday amid a global pandemic that has impacted nearly every aspect of this year's pilgrimage and celebrations. The last days of hajj coincide with the four-day Eid al-Adha, or “Feast of Sacrifice”, in which Muslims slaughter livestock and distribute the meat to the poor. (Photo by Sunday Alamba/AP Photo)

A girl, named Tata and aged 8, wears a Red Army uniform-styled dress during the celebrations of Victory Day, which marks the 78th anniversary of the victory over Nazi Germany in World War Two, in Moscow, Russia on May 9, 2023. (Photo by Shamil Zhumatov/Reuters)

Stanford golfer Rose Shang smiles towards her teammates after winning the NCAA college women's golf championship at Grayhawk Golf Club, Monday, May 22, 2023, in Scottsdale, Ariz. (Photo by Matt York/AP Photo)

A family rides a bike amid rain in Lahore on October 16, 2023. (Photo by Arif Ali/AFP Photo)

Kaori Sakamoto, of Japan, performs her women's short program during the Skate Canada International figure skating competition in Vancouver, British Columbia, Friday, October 27, 2023. (Photo by Darryl Dyck/The Canadian Press via AP Photo)

Armed Yemeni children sit in the back of a pick up truck with fighters loyal to Yemen's Saudi-backed President Abedrabbo Mansour Hadi in the Dar saad neighbourhood of the southern Yemeni city of Aden on May 10, 2015, as they continue to battle Shiite Huthi rebels. (Photo by Saleh Al-Obeidi/AFP 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.

Apple CEO Tim Cook discusses the new iPhone 6 and iPhone 6 plus on Tuesday, September 9, 2014, in Cupertino, Calif. The iPhone 6 will have a screen measuring 4.7 inches, while the iPhone 6 Plus will be 5.5 inches. (Photo by Marcio Jose Sanchez/AP Photo)