I don't now exactly the figure but I am sure it reached millions already.
There are many different experts on social network analysis. One of the most reputable and famous is Karen Stephenson, who has been doing social network analysis for many years.
A social network is a social structure made up of a set of social actors (such as individuals or organizations. Once messages are shared, that's how a social network becomes social media. Many use social media platforms to advertise products and services.
54 members
MyBlogLog was a social network for the blogger community that was based in part on interactions facilitated by a popular web widget that many members install on their blog. The website MyBlogLog was founded in January in 2005.
17 and a half
NASW, also known as National Association of Social Workers, has about 150 thousand members. This association provides services and resources in social benefits field.
wifi network
I know of one: http://www.sailorbits.com . Its active
It influence the lifestyle of many people most especially to teenagers.
"Sarah was a fairly social girl who had many friends and acquaintances."
In April of 2011 there are 27 full members with 5 pending. See the related link for further details.
adult