I saw that article a couple of days ago and don't want to bust anyone's bubble, but there are concerns with it from a statistical perspective
1.) How are they defining and "active user?" They simply just asked people, "Which of the following social networks do you currently have an active profile?" That does not make someone "active" or not
2.) What are the 27 GWI markets? In what markets are the majority of G+s users coming from vs. fB and other competitors?
3.) What was the sample size and how was the research conducted? The question of how many people have more than one G+ account starts to come to mind. (Although the same could be said for more than one of any of those social network accounts--except for maybe LinkedIn)
4.) Supposedly, G+ just past Twitter, LinkedIn and Myspace. Does anyone really believe that these stats are not bizarre? Why wasn't the G+ team making a lot of noise about these achievements if they are consistent?
5.) I don't like any stat that can't be corroborated around at least 2 to 3 other sources/studies. +Tom Anderson
initially posted this "study;" I it made me want to say, shame on him for not looking a bit further into the info.