Google doubling Google+ population

The Google+ team, facing strong demand for the new social-networking service, has expansion on its mind.

Google briefly let Google+ users invite new members last night in a plan to double the social network's population. And Google has begun detailing its plans for letting business users, not just individuals, use the service starting later this year.

Google has been limiting the individual sign-up rate, leading to frustration among many who want to get in. But Dave Besbris, the Google+ engineering director, said last night it was time for another growth spurt.

"Things are going well with the systems right now so we feel comfortable enough to open up invites for a brief period. Our goal is to double the user base in the field trial from its initial group," he said in a Google+ post.

1.7 million Google+ users so far?

Besbris wouldn't say how many people are using Google+ right now, but it's certainly in the thousands at least. Paul Allen, founder of Ancestry.com  and  president of FamilyLink.com, estimated that  there were 1.7 million people on Google+ on Monday, a figure based on a statistical  extrapolation  from  the  frequency of surnames. "My model  uses surname distribution data from the U.S. Census Bureau and compares it to how many Google+ users there currently are with a small sampling of surnames in the U.S. and in the world," he said of his method.

Google+ is a sprawling product, too, and it's taken time for people to grasp its many mechanisms for organizing contacts, sharing posts publicly or selectively, and figuring out details such as, say, the difference between the default stream of contacts' posts (which shows posts from people in all your circles) and the "incoming" stream (which shows posts from people who put you in one of their circles). And Google+ can be used either through a sophisticated Web app or a full-featured Android app; an iOS app for Google+ has been submitted for approval.