Google+ at 10M Users, Analyst Says Social network set to double in size by the weekend By Rob Quinn, Newser Staff Posted Jul 13, 2011 4:15 AM CDT 3 comments Comments "I project that Google will easily pass 10 million users tomorrow and could reach 20 million user by this coming weekend if they keep the Invite Button available," Allen writes. (Google) (Newser) – Google says it is testing Google+ with "a small number of people," but one analyst trying to keep tabs says the social network's population is exploding so fast he can barely keep up. Based on surname analysis, Ancestry.com founder Paul Allen says the social network probably passed 10 million users last night and is on course to hit 20 million by the weekend, reports the Washington Post. "It is easy to underestimate the power of exponential growth," Allen says, estimating that the number of users jumped 350% in just six days after July 4. Google+ isn't the finished version and it has a very long way to go if it is going to match Facebook's 750 million users, but it already feels very "polished and slick," with some features more "obvious and easy to use than those in Facebook," reviewer Katherine Boehret writes at the Wall Street Journal. There have, however, been some growing pains: Users were spammed with multiple error messages last weekend after Google+ ran out of storage space.