At first, it didn't make sense to Jennifer Carvalho.

Her best friend invited her to attend a small networking group organized by the Greater Fort Myers Chamber of Commerce. Carvalho, who works for T&M Portable Restrooms, wasn't sure how she could generate new business by spending time with professionals in retail, law and other industries unrelated to hers.

Until she met a marketer for Robb & Stucky, which furnishes models for builders. She connected Carvalho with builders in need of portable restrooms, which T&M rents out and services in Southwest Florida.

"Who would think that a marketing person for a furniture store could benefit a porta-potty company?" Carvalho says.

As she got to know other group members, Carvalho further experienced the give-and-take fostered by such networking groups. A representative of Sonitrol Security Systems passed her name along to a construction company needing portable restrooms on job sites. And Carvalho got to know an attorney, whom her company hired to pursue deadbeat builders with outstanding bills.

That's all happened in less than a year since joining one of the Chamber's two Professional Networking Groups (PNGs). Each has about 15 to 25 members, who each pay $120 a year.

The catch: Only one person per industry is admitted, and newcomers must get 99 percent of the group's approval in a silent vote. The groups meet twice a month, for either breakfast or lunch, to exchange referrals and market information.

It's not the only option the chamber offers for networking. About a year and a half ago, the Chamber created Women in Business, a group with 80 to 120 professionals who typically attend functions the first Wednesday of every month. It also holds Business After Five events each month.

Immediately after joining the Chamber two years ago, Becky Wilson, an account executive with Aramark Uniform Services, joined a PNG. "I had transferred with Aramark from Tampa to take over this territory, so I was unfamiliar with the area and wanted a way to get to know more about the community and more people in the community," she says.

Wilson joined the group seeking opportunities to generate sales, create friendships and make contacts that might not even be related to her industry. "When I can recommend other businesses and other contacts, it makes me more of a resource," she says.

Wilson and Carvalho advise that success takes work, bringing in leads for others and cultivating relationships.

"People really have to be used to you and want to refer business to you," Wilson says.

Cavalho's advice to potential newcomers: Look at what businesses are members and consider what benefit they will be to your business before joining a networking group. Although it took a few months to parlay her membership into business, Carvalho says, it's been worth it.