The small-business owners are gloomy, gloomy, gloomy.

The summer was wretched, the fall is proceeding poorly, the winter likely to be lost to the high cost of keeping warm. The shoppers are going to malls, or superstores and discounters such as Target, or buying online.

In Harvard Square, there’s desperation over the lack of customers, the national-bank branches greeting visitors from the T and gaping empty storefronts. Rent is down as much as $20 a square foot in parts of the square, according to a local real estate agent, but remains what Chamber of Commerce head Kelly Thompson Clark calls “the biggest concern.”

It certainly is for Frances R. Cardullo, who stood up Thursday at a meeting hosted by the financially ailing Brattle Theatre and challenged the square’s landlords to adapt to current economic realities.

“I’m making a public announcement that two years from now, Cardullo’s will probably not be here,” she said. “If my rent goes up next year, I’m not going to pay.”

Cardullo’s Gourmet Shoppe has been a mainstay of the square for 55 years, but Cardullo says it has never been given its desired lease, even as rent rose in recent years despite a souring local economy. She’s doubtful this will change.

But – griping and sniping all the way, as is city tradition – the owners are fighting back, unified and organized. Inman Square owners recently formed a business association, and there are rumblings of one in Porter Square. This Thursday a steering committee of business owners plan to meet at the home of Laury Hammel, a health club owner who has made it his mission to keep local business scenes in shape around the nation. The Brattle meeting was the first public step in their coordinated campaign to get people to shop “Cambridge Local First.”

“I like that challenge,” Hammel told Cardullo at the Brattle. “I want you here in two years. I want you here in 20 years.”

Some of the effort has already been seen, starting with an Oct. 19 meeting run by the city but well attended by “shop local” members. It revealed that even these longtime residents and fellow business owners didn’t know what services could be found in Cambridge’s iconic square: Among other things, they wanted a deli, forgetting about Cardullo’s; they wanted live music to dance to, forgetting Regattabar; they wanted household items, forgetting Dickson Bros. hardware.

Little wonder that “to raise awareness among consumers, business and government agencies” and to “inform them about the locally owned businesses that exist” are among the group’s bullet points.

Hammel wants Cambridge shoppers to spend at least 10 percent more at locally owned businesses.

“We’re going for the low-hanging fruit, people who shop at the major chains who don’t know the Harvard Book Store is independent, people who are oriented in that direction already. If we increase by 10 percent, that’s a big deal,” Hammel said. “People are really struggling to make it, and we think small, locally owned businesses are the heart and soul of the community.”

Simon Shapiro, of Tag’s Hardware, has been pursuing a “shop local” program for about a year, starting with occasional meetings with city officals. He also has a goal: a different level of taxation for locally owned business.

The doors to his Porter Square store display a decal urging people to shop local, and something similar is planned citywide, along with posters, brochures and public events. As part of the Porter Square Neighbors Association, Shapiro helped produce a map of the shops and services along Massachusetts Avenue between Harvard Square and Arlington. It went into participating stores and to Lesley University students and, by all accounts, was a big hit.

Efforts for the entire city were slower to come along.

Conversations last November between Shapiro, the Harvard Book Store’s Frank Kramer and city development officials Beth Rubenstein and Estella Johnson somehow became conversations in June without much else happening. Shapiro met Hammel in November – and they met again, by coincidence, in June. Now things are in high gear.

Quirks and fissures

All the activity, though, including Hammel’s success in gathering members, reveals some quirks and fissures among Cambridge business owners.

— First among these must be that even the most enduring and prominent members of the Cambridge business community have been strangers to each other. Shapiro, setting up “shop local” meetings with Hammel, “was very impressed with the number of people interested and the breadth of businesses we’ve attracted into this thing.” But until then, he said, “I had never met Gus Rancatore, who runs Toscanini’s ice cream, yet you hear about Toscanini’s all the time. I never knew who Jerry Wolf was, over at the 1369 Coffee House. I said to Frank Kramer, ‘This is amazing.’”

— The disconnect goes on. Gary Drinkwater, who aims to start a Porter Square business association, has been there for a year at his eponymous men’s clothing shop and never met Shapiro, the square’s preeminent business leader. They work within a third of a mile of each other.

— A meeting with Rubenstein and Johnson surprised Shapiro, because, despite a long working relationship with city government, he “wasn’t even aware of how many programs were available for businesses in Cambridge.” The city’s Oct. 19 meeting in Harvard Square was a surprise as well, even to members of the Harvard Square Business Association.

— Finally, knowledge of the city’s previous “shop local” campaign seems nil, and that late-1980s effort could provide meaningful lessons.

The campaign took place when superstore chains such as Framingham-based Staples Inc. were beginning to overshadow smaller retailers. It produced and then gave up on trade shows, created a local business directory and ran an awareness campaign targeting big local companies, such as Polaroid Corp. and Genzyme Corp., that could use and pay for a lot of nearby services.

“I’d say it had moderate success, certainly not great. It certainly raised awareness,” said Karen Swaim Babin, who wasn’t sure why the campaign she led didn’t work better. “It’s tough to compete with those bigger companies. I don’t know how successful we were in attracting purchasing departments of big companies. There was some success.”

Hammel was unfamiliar with her work. He spent years living outside Cambridge before returning three years ago and starting his nationwide drive, starting in Bellingham, Wash., and Salt Lake City and spreading to several cities since. He has flown thousands of miles and estimates he’s spent “half his time” as well as $30,000 in airfare, dues and contributions. And, compared with what Babin experienced here, he says his “shop local” work has begun to pay off strongly in those first communities.

He’s also looking long term.

“This is not a one-year campaign,” he said. “We know this is a 20-year campaign.”