A day after Google unveiled its brand new social networking service Google+, the company decided to open up the invitation process late Wednesday afternoon to those lucky enough to have already been invited to participate in the service.

Previously, the keys to Google+ were only held by those select few who had been allowed in at launch. Thus, an invite was a prized commodity. I was one of those lucky few thanks to Harry McCracken over at Technologizer. Thus I got an early look at Google's new social network.

Gold rush begins, and ends

Google has stressed that Google+ is in its early stages. However, whatever Google was aiming for with its "field trial" must have been successful, because as everyone who was invited in to the service is now able to invite other people in.

Even the second wave of invitees was able to invite friends to join the service.

Better yet, those writing about the decision to open up the invitation process suddenly found themselves popular with readers: TechCrunch's MG Siegler wrote on his Google+ page on his own story that "I'm not sure any TechCrunch post has gotten comments at such a fast rate." Of course you could debate the merits of posting your personal e-mail address just for an invite to another social network, but I digress.

All this attention must have been a bit more than Google bargained for. After about six hours, the company shut the invitation process down over what Google's senior vice president of engineering, Vic Gundotra, called "insane demand."

"We need to do this carefully, and in a controlled way," he posted to his Google+ page late Wednesday night. He did not specify when the invite functionality would return.

Quick public debut a surprise

The sudden coming-out party for Google+ shocked a few people. Some of the earliest invitees said that the search giant was stressing to them to only invite those they knew. Swinging the gates wide open was something they weren't expecting.

Regardless, the way Google is rolling this out may be smart. While the staggered invitation process may frustrate some, in a way it is creating its own buzz. Like the Gmail rollout, you need to know someone in order to get in. It gives Google+ a feeling of exclusivity, and thus creates a desire by those not included to "be in."

Will Google+ succeed long term? That's hard to say. But certainly these first 48 hours have started the social networking "project" off on the right foot.

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