The Growth of Twitter and Facebook Use By Age Demographic

As I noted in my social network audience demographics are always on the move. Even still, there are skeptics who will still doubt that baby boomers are interacting on any network other than InsideFacebook.com put together the following chart that shows not only the growths per age category, but also the ratio of males/females coming to the site per age category.  As you can see, Facebook is experiencing a larger growth in female audiences in every age category but 55-65 year olds, where men are growing at a rate of 19%.  Growth is also lowest in age ranges 18-25 because these audiences are likely to be already on the network.

Do you have any other interesting findings to add? Did any of these growth metrics surprise you?  I'd love to hear your thoughts in the comments below.