According to ComScore, Google Plus has received 20 million visitors in last 21 days. The service has grown significantly between June 29th and July 20th, while it is still in private beta. The service can only be availed through invites.
As of July 19, comScore showed Google+ at just about 20 million visitors worldwide. 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.
The rapid growth of Google+ is not limited to United States but the proliferation on a global basis. While the U.S. leads in Google+ audience, it currently accounts for 27% of the total worldwide audience. India holds a strong #2 position with 2.8 million visitors. The UK (867,000 visitors), Canada (859,000 visitors) and Germany (706,000 visitors) round out the top five.
Early reports had shown that most of the Google Plus users are male. But it seems to be only a early move. Currently males accounts for 63% of visitors while female for the remaining 37%. In addition, 58% of the total Google+ audience is between the ages of 18-34, with 25-34 year olds representing more than 1/3rd of the total.