Here is a link to a blog by Jim Moore which contains a synopis and link to the Pew report on internet usage by Americans. Which contains , to me, the amazing statistic that 44% of internet users have CONTRIBUTED to online content.
However, there classification of content creators into three types, seems a bit flawed. They have:-
Power Creators – average age of 25
Content Omnivores – average age 40
Older Creators – average for this group is 58
Trouble is if you read the report I fit into all three categories quite comfortably. I wonder why age is such an issue with those guys?