The extraordinary growth in subscribers for the Google+ social media has primarily driven by people in the US and India.

According to, Google+ has amassed 20-million unique visitors in its first three weeks of operation (through July 19) – an 82 percent jump from the prior week and 561 percent higher than two weeks ago.

In the U.S. alone, more than 5-million visitors have gone on Google+.

ComScore indicated that the U.S. accounts for 27 percent of the global audience for Google+, with India in second place with 2.8-million visitors. Thereafter, the largest numbers come from Britain (867,000 visitors), Canada (859,000 visitors) and Germany (706,000 visitors) round out the top five.

“It would be difficult to think of many sites that reached such a large number in such a short period of time,” wrote a ComScore blogger. “That said, Google does have a built-in visitor base of more than 1 billion to work with, so there is clearly potential to convert a high number of users to its new social tool – even if it is still invite-only.”

Moreover, 58 percent of the total Google+ audience is in the 18-34 age bracket.

“Time will ultimately tell if Google+ can leverage its early momentum to reach critical mass among users and capture a firm foothold in the well-established social networking market,” ComScore blogger wrote.