Customers at these special facilities order like normal, but the cashiers simply suggest payment amounts - what customers actually put into the donation box is up to them.
Panera founder and chairman Ronald Shaich says nearly 80 percent of customers pay the full prices or more.
"The singular thing we've learned is that humanity is fundamentally good," Shaich said. "People have essentially been doing the right thing. People get it, people respond to it, they don't abuse it. I think at first some people thought that they would abuse us."
All proceeds go toward a non-profit foundation as well as a job training program for youth.
Panera's first pay-what-you-want location was in opened in Clayton. The company has since opened two other facilities in Detroit and Portland, Oregon.