BOSTON (CBS) – A national chain restaurant is opening specialty shops allowing customers to pay what they can afford, or even nothing at all, for their meals.

A bowl of soup, a piece of bread, and a helping of charity. It is a formula Panera Bread Company is using at new Panera Cares Cafes all over the country. The latest location will be here in Boston, right across from City Hall.

There are four of these non-profit restaurants currently operating in Michigan, Illinois, Oregon and Missouri. Boston will be the fifth.

There are no cash registers, just donation jars. The menu doesn’t offer prices, just suggested donations. Panera’s co-CEO and founder Ron Schaich has called it an experiment in human nature.

“This isn’t a soup kitchen. This isn’t a homeless shelter. It’s a cafe of shared responsibility,” Shaich told CBS News in 2010.

Outside the soon to open Boston location, potential customers liked the idea.

“I think it’s a good idea because you get a lot of people who can afford, being a business area. And there’s probably a lot of homeless in the area,” said Jesse Redstone, a North End resident.

And that is the point according to Shaich. He says the stores open in areas where they can be sustained but also where they can help people.

At the four non-profit restaurants currently operating in other cities, the restaurants bring in about 75 percent of the revenue of retail Panera restaurants, according to the Boston Globe.

The company estimates that 60 percent of customers pay regular price for their food. 20 percent donate more money and 20 percent pay less than cost or nothing at all.