Thanks to information compiled by Brian Solis
( http://www.briansolis.com/2009/10/revealing-the-people-defining-social-networks/ )
and visualized by http://informationisbeautiful.net, we can see that women are more active on most social media sites, with very few exceptions.
I guess the next study needs to be, What are women discussing, creating, viewing and sharing on these sites? I think the results may be much more unconventional than ever before, as today’s women have become more educated and are more active (in terms of community, religion, art, sport and business) than ever seen in recorded history.