An estimated 1.61 billion people, more than one in five globally, will log in to social networking sites at least monthly this year, the research firm eMarketer said Tuesday.
The study said the number was up 14.2 percent from a year ago and growth will push that number up to 2.33 billion by 2017.
The highest penetration of social network users, according to eMarketer, is in the Netherlands, at 63.5 percent. Norway was second at 63.3 percent, followed by Sweden (56.4 percent), South Korea (54.4 percent), Denmark (53.3 percent), the United States (51.7 percent) and Finland (51.3 percent)....
Unfortunately, I can't find the original study on eMarketer's web site. The methodology is of interest, since this article says "log in to social networking sites" and it isn't clear if the 1.6 counts unique people, or unique accounts, since the same person could have multiple accounts on different social networks. I'd also like to know what counts as "social media" since the boundary of what's called "social media" has a lot of gray areas like photo sharing sites. The article raises more questions than it answers.
This link is to an AFP wire article I have seen reprinted all over the web, but I can't find any other articles that talk about the study. (Or give links to it.)