Nick D'Ambrosia already spent a month in the North Bay last fall doing business with fans of the San Francisco Giants, the new World Series champs.

Now the young man from Hamden, Conn., is waiting to see whether the Bay Area's 49ers will prevail Sunday against the Baltimore Ravens. Such a victory would extend his visit to Sonoma County selling red shirts, caps and other products at a makeshift booth in Rohnert Park.

"If they win, I'll be here another two weeks after the game," said D'Ambrosia, 25, as he hung up a T-shirt in a tent at a supermarket parking lot at Commerce Boulevard and Rohnert Park Expressway.

A Niners win, he said, would result in especially brisk business because "a lot of people are just waiting to buy" apparel and other products that proclaim the team a Super Bowl champion once more.

The 49ers' quest for the Vince Lombardi trophy has prompted sports paraphernalia companies from across the country to temporarily set up shop in Sonoma County. Working out of gas stations and parking lots, salesmen say demand is strong for a range of products they tout as officially licensed by the National Football League, complete with shiny silver badges and NFL-emblazoned tags.

Along with T-shirts and sweatshirts, the booths offer full-color Super Bowl programs and commemorative footballs, ties, dog dishes, logos, flags and banners. Pennants combine the faces of 49ers coach Jim Harbaugh and his brother, Ravens coach John Harbaugh, beneath the title, "Super Bro."

D'Ambrosia, decked out in a yellow Pittsburgh Penguins hockey cap, works for his family's Connecticut-based business, N&D Sports. Along with Rohnert Park, he said, the company has booths set up in Petaluma, Novato, Mill Valley and three cities on the Peninsula.

Besides N&D, Missouri-based Shallow Concessions has set up concession booths in Sonoma County. On Friday, Barry Dantzer manned one of its booths at a service station at Guerneville and Marlow roads.

The company, Dantzer said, is selling 49ers goods at 11 locations between San Anselmo and Santa Rosa.

Both companies have been in business for years, working professional and college sports, the two men said. Next up for both is The Final Four, college basketball's national championship.

Dantzer, who lives in Ashtabula, Ohio, said he came out to sell Niners goods in 1995 when the team last went to the Super Bowl and defeated the San Diego Chargers.

However, in late October he was working in Detroit when the Giants swept the Tigers.

"We got killed," he recalled of sales. "It was no fun ... cold weather and a losing team."

Dantzer on Friday offered shirts from $15 to $65. Earrings were $10 and a regulation white football went for $40.

D'Ambrosia was selling caps for $25 and $35, a foam finger for $10 and a black Super Bowl XLVII sweatshirt for $60.

Sales of NFL products totaled $3.3 billion in 2010, according to ESPN. Major League Baseball product sales were even greater, at $5 billion.

Not surprisingly, such figures attract plenty of bootleggers. This week, U.S. Immigration and Customs Enforcement officials announced they had seized a record $13.6 million in fake sports gear this season. The federal agency arrested 23 people and seized 313 websites that were selling the merchandise.

However, both D'Ambrosia and Dantzer insist their goods are authentic and their companies operate legally. Dantzer pointed to the City of Santa Rosa use permit he displays at his booth, and said that both his company and N&D do business "all above the table."

Said D'Ambrosia: "I think everybody has a right to make money, as long as we're doing it legally."

However, the owner of a Santa Rosa sports apparel shop maintained the temporary booths hurt his business.

"These people aren't doing anything for your community," said Tony Adamo, owner of All American Sports Fan, which has 10 stores in California and Nevada, including one at Coddingtown Mall in Santa Rosa. In contrast, he said, his store gives jobs to local residents.

A quarter century ago, a 49ers appearance in the Super Bowl could bring in more than $30,000 a day to one of his stores, said Adamo, who is based in Fresno.

"Those days are gone," he said. "The markets are flooded."

He estimated his stores now are likely to do about half of what they did back in the biggest Super Bowls. His business is competing with other merchants, Internet sales and bootlegged goods, he said.

On Friday afternoon, a steady stream of fans visited both D'Ambrosia's and Dantzer's booths. Many already were adorned in team gear, including Teri Powell of Windsor. The red jersey she wore in Rohnert Park was the first of three different tops she planned to wear through Sunday "cause it's 49er weekend."

At Dantzer's booth, Larry Seaton of Concord stopped to purchase three pennants and $20 worth of logos. Seaton, who "had the time of my life" attending the 49ers' victory over the Atlanta Falcons last month, said he planned to send some of the goods by overnight mail to friends for their Super Bowl parties.

"And I want to keep some of it for myself," he said.

You can reach Staff Writer Robert Digitale at 521-5285 or robert.digitale@pressdemocrat.com.