Charity Nash had never heard of cash mobbing before a "mob" arrived one Friday in April at Cookie Express, a family owned bakery in Peachtree City. It wasn't really a mob, but the 15 to 20 people who showed up did buy baked goods, and a few became regular customers. "It showed us that the people of Peachtree City care about small businesses," Nash said.

Since launching just under a year ago in upstate New York, Cash Mob is poised to become the newest, quickest, most grassroots way for businesses to get a shot of publicity and, hopefully, an infusion of cash. All it takes is an organizer to designate a business, set a day and time, then promote like crazy on social media asking people to show up and spend a minimum amount of cash, typically $10 to $20.

"Right now it is the biggest it has been since it started last fall," said Suzanne Obszanski, director of promotion and marketing for Cash Mob. "We have seen people taking a unique approach depending on where they live and what they need."

Cash mobbing came to Atlanta when Big Peach Running Company in Brookhaven was mobbed in March. The store for runners and walkers earned $320 in sales in less than one hour, according to Cash Mob. Since then, Georgia has averaged one cash mob a month, Obszanski said.

Though most cash mobbing takes place at retail shops or eateries, some mobs have been service based, Internet based or based on community votes. This weekend, the National Black Arts Festival is calling on Atlantans to cash mob the three-day International Marketplace at Centennial Olympic Park.

"We decided to do it because the idea of activating a local community to support a local business appeals to me," said Michael Simanga, executive director of NBAF. "We are a nonprofit but we are still a business and we need the support of our customer base."

This year, the marketplace features about 75 vendors from the African diaspora and countries including Jamaica and Ghana selling products that range from paintings and textiles to leather goods and ceramics.

"We hope that people will have the response of being interested and amused" by the cash mob "but will also come out to the park and have a great time and spend some money with our vendors," Simanga said.

While they won't be able to track sales that result from cash mobbing, Simanga said they plan to monitor foot traffic and are asking vendors to survey attendees on their awareness of the cash mob.

To help promote the event, NBAF has launched its biggest social media campaign ever, Simanga said — tweeting, Facebooking and blogging — in addition to using more traditional email and media placements.

Cash Mob assists with publicity by providing fliers and a page on CashMob.com, but engaging customers via social media is key to successful cash mobbing, Obszanski said.

For a trend that is not quite a year old, sometimes even that isn't enough.

Kim Julian, a business consultant, had recently relocated to the metro area from Colorado when she corralled several businesses in Peachtree City to be cash mob sites.

"I just want to heighten people's awareness about how important it is to buy locally from a small retailer," Julian said. She had already witnessed the shuttering of a favorite Italian eatery and thought something like Cash Mob might have helped.

The first event at Cookie Express went well, but a followup mob at a hardware store in the area fell short.

"Nobody showed up," said Brent Lambert, co-manager of Gill-Roy's Hardware. "We were expecting 20 to 30 people at 10 bucks a pop. We maybe had three or four people show up."

Though Cash Mob was envisioned as a spontaneous event where people simply appear at a store with money in hand in a short time period, Julian realized Peachtree City required a different approach. "The challenge in Peachtree City is scheduling. It is like planning a birthday party," Julian said. "It is impossible to come up with a good time frame, so you just do a large window" of time, "but you don't get that mob feel."

Unlike group buying services, Cash Mob doesn't cost the business anything, so as Lambert said, if it doesn't pan out, it is no loss.

Julian and others believe as more people hear about Cash Mob and learn what cash mobbing is, the impact will be more dramatic. "The bottom result is we want [businesses] to get more business," Julian said. "However that can be attained is great."

National Black Arts Festival - International Marketplace Cash Mob

8 a.m. - 10 p.m. Fri. - Sat.; 9 a.m. - 6 p.m. Sun. Event is free, cash mob is set for $20.

265 Park Avenue West NW

404.730.7315. www.nbaf.org.