A "small town" couple in North Dakota refurbished a decaying building in downtown Valley City to make a new self-serve coffee shop. With the Keurig brewing system, or K-Cups, the shop is entirely do-it-yourself — including the payments.

To cut down on costs, David Brekke, who works as a business consultant from home, and his wife run The Vault Coffee Shop and Bakery on the honor system, complete with a credit card swipe machine and a slot into which customers can drop cash or checks.

"Just keep track of your purchases and enter in the appropriate amount," says a sign at the desk. "Exact change is not necessary, round down and give yourself a break or round up and help us stay in business."

And, in the first 10 months of business, customers did just that — paying 15 percent above the asking price.

"Many people ask how we are not being robbed blind," wrote the couple on their website. "A lessor factor is that we have cameras – though their primary purpose is to help provide a safe atmosphere."

They believe the more important factor is the goodness of the people of Valley City which makes them "more generous than dishonest".

(WATCH the NBC video below or READ the AP story via Kansas City Star) Story tip from Olivia Leyton