After movie rentals began to decline, Shelf tacked a plant business onto the back of the shop two years ago. In addition to succulents, the store sells ceramic and glass planters handcrafted by local artists and offers classes on building terrariums and vertical gardens.
An early backer of Bernal Bucks, Shelf said the "economic implosion of 2008" prompted him to spend more at local businesses and urge others to do the same. "It's kind of cool," he said, "knowing that you're keeping people's families going."
Josh Donald, owner of Bernal Cutlery, is another believer.
"I love the idea of a local currency," said Donald, who like others here moved his accounts from a corporate bank to the credit union while signing up for the card.
But Donald is still waiting for a customer to present him with a Bernal Bucks coupon. That may be because shoppers are saving up their credits.
Among them is Brigitte Phipps, a young mother who runs her husband's chiropractic office. She has accrued $100 in Bernal Bucks — her 5% return on $2,000 in purchases from the Good Life Grocery — but has yet to decide where to spend them or whether to give them away.
"I think it's pretty awesome," she said. "I don't leave the hill."
As for the nonprofit donations, Hesse and Lebleu said they are building slowly.
Some cardholders give a fixed percentage of their bucks to the elementary school's PTA, while others have chosen the Bernal Heights Neighborhood Center, which offers programs for low-income youth and seniors.
As six elderly women in black top hats tap-danced in the community room recently, Ebora, the executive director, showed off her brand-new Bernal Bucks card. (According to credit union manager Carlos Brenes, 20 or so users sign up every month.)
Last month, she said, the center accrued $50 in Bernal Bucks donations. The amount may seem small, but Ebora said it would pay for a month of hot lunches for one senior.
"Any little bit helps, especially with the decline in public funding," she said.
The program taps into a growing desire to transact business on a more intimate level.
"People are recognizing that dollars are basically scarce right now," said Janelle Orsi of Oakland's Sustainable Economies Law Center. But even when you don't have the real dollars, she said, you still have something of value.
Orsi said she often is approached by clients seeking to pay for legal services in unconventional ways. In exchange for recent advice to a food cooperative south of San Francisco, for example, Orsi was offered lessons in "bird language."
"Money is so weird," she said. "It only has value if people are willing to accept it."