Google+ Could be Bigger than LinkedIn, Twitter in a Year - Now Comes the Tough Part

Google+'s (limited) success story is only a small first step for the social network. It's been able to get perhaps 20 million users and 25 million visitors in the first month or so it's been available.

But as with any new thing, people are drawn in by curiosity, but some don't stick around after they satisfy the initial urge.

Google+ may have gotten just enough users to stick around though and enough momentum to maintain growth even after the inevitable, and already happening, lull in adding new users.

One survey, based on a little over 1,000 people, indicates that Google+ may end up being used by some 22 percent of Americans in a year, up from 13 percent now.

That would put it ahead of established social networks such as Twitter and LinkedIn, both of which are expected to reach about 20 percent of US adults in a year's time.

Of course, that's still far behind Facebook's 69 percent reach, which will actually be lower than today's 71 percent.

What's encouraging for Google+ is the retention rate, according to the study, 45 percent of those that had signed up for a Google+ account checked in to see what's new every day. For Facebook the figure is 62 percent.

Still, Google+ is at a crucial point. The initial interest is mostly gone, though there may still be some people wanting to get in, the social network is not open to anyone just yet, you need an invite.

From now on, Google faces the much tougher task of getting people to join based on the people that are already in, the viral factor that fuels every social network out there.

It's a lot harder to get 'regular users' to join than it is to get early adopters, but with 20 million registered users, almost half of which are visiting the site each day, or at least every several days, it could be enough for the site to keep going and to entice others to come in.