As charities plunge into the world of social networking — but struggle to raise money from their efforts — they may find intriguing this story about fund raising and Facebook, recounted by Ken Goldstein on The Nonprofit Consultant Blog.

Last month, when Jenni Ware lost her wallet at a California supermarket, a fellow customer she’d never met before, Carolee Hazard, offered to pay her $207 grocery bill. Later that day, Ms. Ware found her wallet and sent Ms. Hazard $300 — the food bill, plus an extra $93 for her trouble.

Ms. Hazard, a Facebook user, asked her online “friends” what they would do with the extra money. As people suggested she donate the amount to charity, Ms. Hazard not only donated Ms. Ware’s $93 tip, but matched the amount. So did several of her Facebook connections.

“The result for Second Harvest Food Bank of Santa Clara and San Mateo counties, where it all began? Nearly $10,000 raised for Silicon Valley’s hungry in a week — the most raised in such a short period of time, according to the food bank,” writes Mr. Goldstein.

Ms. Hazard has started the 93 Dollar Club on Facebook, which allows people worldwide to read about the story and donate to food banks in their local areas. Writes Mr. Goldstein, “Commenters say they are reading – and giving – from Iran, Israel, Spain, Portugal, Turkey, the Czech Republic, Australia, Hungary, Sri Lanka and beyond.”

He concludes, “An old expression about good press coverage is that it’s like ‘advertising you can’t buy.’ Well, good viral fund raising is pretty much the same. To be truly ‘viral’ it has to come from your supporters, not your staff, and it has to come on their schedule, not yours, and it has to be their ideas.

Has your organization had success raising money via social networks like Facebook? Click on the “comments” link below to share your story.