The difference is, the company is giving many Google Voice services away for free, rather than charging for them. Why?
Google Voice,what can you do?
Google Voice is one of the coolest, most useful new services to come out in a long time. It’s especially great for digital nomad types and business people who are already heavy users of the telephone. Note that Google is slowly rolling out the service, and it’s currently offered by invitation only.

The main use of Google Voice is that all your phones — work and personal, landline and mobile — are connected. These connections are managed under your regular Google (Gmail) username and password. Google gives you a new telephone number, and all phones are reachable via that number.

You can choose exactly which of your phones ring for each caller. For example, if your spouse calls, it can ring all phones. If your boss calls, just your work landline rings. And, of course, if the IRS calls, it can ring none of your phones! Google Voice has a “Spam” function that automatically blocks sales calls. A block caller” feature lies for you, playing the “number has been disconnected or is no longer in service” message for any phone number you specify.

Google Voice enables you to listen while a caller is leaving a voicemail, just like an answering machine does. You can record a custom voicemail greeting for groups, or even for individuals. Google Voice lets you check voicemail from any of the phones you’ve authorized. You can also check via “visual voicemail,” which looks like e-mail. Voicemails are transcribed by default, so you can read them rather than listen to them if you like. You can choose to get your voicemails as SMS or e-mails, and can even reply via SMS.

During a call, just push a button to add new callers to existing conversations. Push another to actually record incoming calls (it notifies the caller that the recording feature is on). Google Voice lets you e-mail the recording to yourself, download it as an MP3 file or even embed it into a Web page. Google Voice will probably grow virally as bloggers embed recorded telephone interviews into their blogs.

Google Voice is cool, but it’s not perfect. Users report issues with the SMS feature. (In my experience, SMS on the Web never works right.) Other features are less than perfectly reliable also. Users have reported a wide range of small problems doing things like deleting voicemail and the slow delivery of transcriptions. Google publishes a list of known issues.

Another problem is with the phone numbers. Most people don’t want to give up their existing number. Google hopes to allow users to port their current numbers in the future. Caller ID and SMS identification from Google Voice users can be problematic. If someone , for example, sends you an SMS or calls one of your numbers, the return SMS or call shows your Google virtual number. People have been struggling with this.

Ezra Gottheil, an analyst at Technology Business Research Inc., noted that while Microsoft is busy going after Google’s search market, Google is using the billboard campaign it go after Microsoft’s bread-and-butter Office suite.
“Each company is targeting the other right now,” said Gottheil. “They’re laying the groundwork for what they both see as an inevitable collision in the future. Right now, neither company is deriving much revenue from its presence in the other’s space… Microsoft is more vulnerable because they must cannibalize some of their current application revenue to expand their application market, where Google only has to maintain a rough technical equivalence with Microsoft to maintain its search franchise.”
Google’s ad campaign and Microsoft’s deal with Yahoo are just the latest moves in this ongoing fight between industry giants.

In June, Microsoft unveiled its new search engine, Bing, an update to its far-from-beloved Microsoft Live Search. And with Microsoft’s advertising power and a lot of media attention behind it, Bing has shown strong numbers just out of the gate. But with only 8.23% of the market, Bing has done little more than nibble away at Google share, which is just over more than 78% of the search market.

StatCounter CEO Aodhan Cullen described Bing’s progress in the market as “steady, if not spectacular.”
For its part, Yahoo two weeks ago unveiled a beta of its newly overhauled homepage, whose promised features include the ability to integrate with social networking sites like Facebook, Twitter and Myspace. The changes are an apparent attempt to recapture some of the hip cachet the site had during its heyday.
The problem for Microsoft and Yahoo is that despite their efforts, Google still looms far ahead of both. And Google is aiming its sights on the enterprise.
Last month, Google took the training wheels off several key hosted Google Apps offerings that have spent years in beta-test mode. The beta label came off some main Google Apps services, including Gmail, Google Calendar, Google Talk and Google Docs.
Analysts were quick to note that it’s a move geared to making Google Apps more appealing to enterprise users. With similar intent, Google this year also has come out with offline access and support for BlackBerry and Outlook users.