comScore: Three weeks in, Google+ has a global audience of 20 million visitors, goes big in India

Following Ancestry.com founder Paul Allen’s estimate that Google+ amassed ten million accounts in just two weeks and the subsequent confirmation from Google, comScore is out today with fresh stats derived from cumulative unique visitor data from around the world. While the research firm did not attempt to estimate the number of unique user accounts, they found out that about 20 million unique visitors worldwide loaded Google+ pages as of July 19, just three weeks after the service debuted:

The evidence shows that Google+ is off to a strong start in its first few weeks with a global audience of 20 million visitors. It has clearly captured the attention of the technorati and as usage incubates among this crowd it will likely continue to proliferate to a more general audience. That number represents an increase of 82% from the previous week and 561% vs. two weeks prior. The U.S. audience recently surpassed 5 million visitors, up 81% from the previous week and 723% from two weeks earlier.

Their data is based on unique visitors and includes visits from both Google+ users and non-users who may have visited plus.google.com pages. Bear in mind that the numbers exclude visits from mobile devices and usage that occurs through the Google+ bar at the top of most Google pages. Google+ seems to be off to a great start everywhere, with 63 percent visits from abroad. The top five non-US markets include India with 2.8 million visitors, the UK (867,000 visitors), Canada (859,000 visitors) and Germany (706,000 visitors). More interesting data points right below the fold.

In the US, nearly two out of three visitors are male (63 percent) and well above half the visits (58 percent) came from users aged between 18-34, with 25-34 year olds representing more than one-third of the total. Google+-friendly places in the US include Austin, San Francisco, Minneapolis, Pittsburgh and Washington, DC. comScore’s Andrew Lipsan bets on the network effect boosting Google+ numbers exponentially. If we may add, celebrity accounts and acquisitions of social startups here and there should do the trick as well. And we’re just getting started. As in, Google+ is currently in a limited, invite-only state. If you have a Google+ account, you may want to check out our tips to managing your Google+ identity.