Once, only teens and techies had blogs. Details from last night’s date and opinions about the latest video games filled these first Web-based logs, which started popping up around 1999.

Today, more and more businesses are joining the blogging world. What began as a mere pastime has become a valuable promotional tool and internal communication vehicle for firms of all types and sizes, from small entrepreneurships to Fortune 500 giants.

Take the Rotarian-owned company NetworkInAustin.com. With 350 subscribers, this local business networking resource, based in Austin, Texas, USA, is one of a growing number of companies worldwide that have started external blogs to help advertise their services and communicate with customers.

“Business owners blog to demonstrate their expertise, project an image, show that they’re current, build credibility, and generate a sense of community,” says Scott Ingram, founder of NetworkInAustin.com and a member of the Rotary Club of Downtown Austin.

An external blog can allow your company to interact with a mass audience. More current than a Web site and more far-reaching than a mass e-mail, a blog allows anyone with approval to post content at any time. Bloggers can add new information whenever they want, and they can receive feedback as often as others contribute to the discussion.

“The content of your blog depends on who you want to reach – shareholders, customers, other people in your industry, or your own staff,” says Ingram. Business blogs may contain anything from product updates and trade news to opinions, commentary, and personal stories. “Basically, it’s whatever you want it to be,” he adds. The NetworkInAustin.com blog offers networking tips and advice for business owners.

Just like their predecessors, many of today’s corporate blogs encourage a personal connection with customers by conveying a casual tone, sometimes with a personal note. “My blog is about building business connections, but it’s also about me and my family and what’s going on in my life,” Ingram explains.

Some blogs, such as the one Rotarian Jim Blasingame started for his radio show (www.jimsblog.biz), also feature audio. Blasingame, of the Rotary Club of The Greater Shoals Area/Sheffield, Ala., USA, hosts a nationally syndicated radio program called The Small Business Advocate, which doles out advice to small-business owners.

“When we created ours in August 2005, we wanted to make it easier for our Internet customers to have access to and benefit from my articles, as well as tips from the small-business experts featured on my radio program,” Blasingame explains. “Our blog brings the newest information we can provide right to our customers, every day. If you were in the bakery business, you’d put the freshest rolls in the window so people could see the steam rising from them. Well, we put our freshest out front in our blog.”

Blogging business owners have enjoyed increased publicity and consumer feedback. “The PR attention from my blog far surpasses anything I’ve ever done,” Ingram says. “And blogs are a great marketing tool, since you can learn how people perceive you and your business.”

Of course, blogs can have a downside: Companies have to be ready to react to negative postings. “You can screen any that you feel are inappropriate, preventing them from appearing on your blog,” says Blasingame. Though it’s possible to edit or delete posted comments from readers, your company should have a strategy for dealing with unfavorable posts before starting an external blog.

The dedication and commitment required to maintain a blog is another potential drawback. Managers need to devote time to pondering, writing, and responding to content. “If you’re trying to gauge your market and stimulate discussion, you have to think about customers’ comments and what you’re going to say to them,” says Evan Carmichael, publisher of a blog for entrepreneurs in Toronto.

So, before you set up a blog for your business, ask yourself, Can I capitalize on the benefits? Can I make a commitment? Do I have enough to say? “A blog doesn’t have to take a lot of time,” says Ingram. “And if you think you have nothing to write about, think again. The truth is, you’re an expert. All you have to do is put your expertise into words. Then, if you need help, have someone write your blog for you. But don’t do a blog if you can’t keep it up, you’re uncomfortable with it reaching so many people, or you fear the content may be a liability for you.”

If you do decide to create a blog, “they are a great way to build community with customers. And that’s the key to business success in the 21st century,” Blasingame says.