ComScore said Google+ has got more than 20 million users, including 5 million users in the U.S., in the first 3 weeks since the search engine launched the social network as an alternative to Facebook Inc.
The Researcher estimates from unique visitors who arrived at Google+ from June 29 through July 19, said Andrew Lipsman, vice president of industry analysis at ComScore.

"As of July 19, ComScore showed Google+ at just about 20 million users worldwide, an extraordinary number in just its first 3 weeks," Lipsman said, adding that the figure represents an increase of 82 percent from the previous week and 561 percent vs. 2 weeks prior."
The Google Plus (+) U.S. audience paced the field, surpassing 5 million users, up 81 percent from the previous week and 723 percent from 2 weeks earlier.
But Google Plus (+) global growth is impressive to Lipsman, who noted that while the U.S. leads in Google Plus (+) audience, India is No. 2 with 2.8 million users. The U.K. has (867,000 users), Canada (859,000 users) and Germany (706,000 users) rounded out the top 5.
The Google Plus (+) numbers could be even greater because ComScore didn't count visitors from mobile phones. Lipsman said he excluded visits from iPhone and Android smartphone users, limiting estimates to those who navigated to plus.google.com pages from home and work computers.

Vic Gundotra, Google's vice president of engineering overseeing Google Plus (+), said in response to Search Engine Land Editor Danny Sullivan's open letter on Google Plus (+): "We should have already predicted brands and people who want a following would be very frustrated when we didn't have proper profile support."

"Your enthusiasm obligates us to do more to get businesses involved in Google+ in the right way, and we have to do it faster," Oestlein acknowledged. "As a result, we have refocused a few priorities, and we expect to have an initial version of businesses profiles up and running for everyone in the next few months."