There is a single source to derive blog traffic - widget. If you use a proper widget you can derive more visitors from social sites. About it - "By the widget all the visitors will know your activities from the blog also. Your profile lead your activities and the widget will show others."

Source : http://blogsexpression.blogspot.com/

so a widget can drive traffic? this is new to me.

The only widget i am using is the blogrush and mybloglog widget.

I thought you needed to use organic methods of internet marketing?