In three weeks
Google+ seems to be doing rather well and early stats indicate that the new service managed to attract nearly 20 million users over the past three weeks.
Since July 7, the number soared from about 2 million to 18 million on July 18. As of Monday, Google+ was getting 750,000 new users a day.
Google is hoping to see as many as one million new users a day, but even at that pace it will take some time before Google+ comes close to Facebook’s 750 million users.