Google+ is off to a big start, with almost 20 million unique visitors in its three weeks of existence.
According to Comscore, most of those visitors — 5.3 million — are from the U.S. More surprising is that number-two country India already has 2.8 million unique visitors, almost half as many as the U.S. All other countries are way down the list with less than a million.
India is also well represented on Facebook, with 31 million registered users, behind only Indonesia (36 million) and the U.S. (153 million), according to CheckFacebook.com.
Comscore is measuring unique visitors, not registered users. Last week on its earnings call, Google confirmed that the social network has more than 10 million registered users. Also, the Comscore figures do not measure mobile usage or visitors who only use the black Google+ toolbar — for instance, it’s possible to read and respond to notifications through the toolbar without ever visiting plus.google.com. But users have to sign up by visiting the Web site, so it’s doubtful that Comscore is undercounting.
Comscore stats are a little more bullish than an analysis this week Experian Hitwise, found that the Google+ site got only 1.8 million visits — not unique users, but one-time visits — from the U.S. last week. That suggests that a lot of people may be signing up and then never returning to the site, or visiting only through the black toolbar (which Experian does not count either).
Here are the full Comscore stats for Google+ by country (number three is the U.K.):