Is Google Voice good enough to use for business? The answer is a resounding "yes" for Lyn Mettler, co-owner of Step Ahead, a social media marketing company. Mettler began using the service when she lived and ran her business in Charleston, S.C. At the time, she and her small staff worked out of their homes and Mettler wanted to eliminate her land line. But her cell phone, part of a plan shared among her family, had an Atlanta area code. She didn't want to change mobile plans, but she did want her Charleston customers to have a local number where they could reach her. She signed up for Google Voice, which forwards calls to any number or numbers you wish.

The service became even more useful more recently, when she moved to Indianapolis. "Now my Charleston customers can still call me on a Charleston number, which makes them feel like I'm not so far away," she says. "My Indianapolis customers call me on an Indianapolis number. And it all rings to the same phone."

To her surprise, she also found Google Voice improved work flow. "What I like about it that I didn't expect is that voicemail messages arrive in email." That's handy, since most customers call Mettler's number with questions or concerns, and she hands them off to whichever team member is working on that project. Instead of having to compose an e-mail or have a conversation about the client's question, she now simply forwards the phone message itself.

For Barry Greenstein, co-founder of bGreen lifestyle + building, Google Voice makes an all-mobile operation workable. bGreen sells environmentally friendly flooring and other building supplies, so it makes sense to have a mobile showroom -- a refitted van --rather than a stationary office. Greenstein says he hasn't had a land line in years -- and in any case, without a traditional office, there was no place to install one. On the other hand, he didn't want his business number to be recognizable as mobile, so he uses a Google Voice number instead. An added benefit is that voicemail messages go to both Greenstein and his business partner, so they get the same information at the same time

Powerful features

Anyone familiar with Google Voice knows that these are only a small portion of what the service can do. It also keeps a record of every incoming and outgoing call, text, and voicemail, lets users create special greetings for particular callers, allows for blocking specific numbers, call screening, and even for listening in on a caller's voicemail and picking up mid-stream, among many others.

Its most-mocked feature is also the most unusual: Google Voice attempts to create a transcript of every voicemail, and sends that transcript as an e-mail and text message. Needless to say, errors are common -- "Hi Minda" becomes "I'm in the" -- for instance. But, flawed as they are, these transcripts can be hugely useful. "Ninety percent of the time, I don't even listen to the message, because the transcript gives me a general idea of who left the message and what it was about," Greenstein says.

"With a text of the transcript, I can check my voicemail while I'm in a meeting, and find out if it's anything urgent," says Dave Michels, a consultant and analyst who closely follows unified communications, and author of the blog Pin Drop Soup. "That isn't an easy feature to get elsewhere."

Possibly, Google Voice's most powerful feature is its cost: $0 for the service, $0 for calls within the United States and Canada, and very low rates, starting a $.02 per minute, for international calls. That's a powerful incentive for a startup or small company on a tight budget. "We use every Google product we can because they're free and good," Greenstein says. In the absence of Google Voice, he says, he would look for the lowest cost VoIP solution available, or use a Skype phone number.

No guarantees

But if Google Voice offers huge benefits, it also has a few drawbacks that businesses should know up front. First, there's no support. If you encounter a problem, your only recourse is the online FAQ and user forums. "If you're not a little tech-savvy, you might get lost," Greenstein says.

There's also no service level agreement, which means no guarantee of how reliable the service will be. Indeed, it has had occasional outages, though most were relatively brief. "I have had some people say they got a busy signal on one of the numbers," Mettler reports. "I'm not sure whether that was an issue with Google Voice or with my iPhone. And I have had people occasionally say a number just rang and rang, without going to voicemail."

Another possible drawback for businesses is that Google Voice is designed for individual users who control their own phone numbers. There's no option for centralized administration. This means that a departing salesperson can take his or her phone number along, which makes it extra-easy to take customers along too. Also, Google Voice does not currently allow users to import their existing phone numbers. But Michels speculates that both features will be offered if Google someday introduces a business-class version of Google Voice, akin to Gmail for Business.

Perhaps its most worrisome down side is that it comes with a degree of uncertainty. "There's a lot of risk using any service you don't really own, and people underestimate that," Michels says. If an employee using Google Voice violates its terms of service, you might find that number or numbers abruptly cut off. Or, the company could simply decide to discontinue Google Voice altogether, as it recently did with another highly popular free service, 1-800-GOOG-411.

This is not to say that you shouldn't use Google Voice -- it's a valuable tool for many businesses. But, Michels advises, go into it knowing the risks. "Google Voice must cost the company a lot of money. It has no advertising so it isn't generating much revenue. What could their plan possibly be? It's fun to have those conversations. But the last thing you should do is assume that the service will be available --or free -- forever."