A colleague recently highlighted a few social media metrics from Avinash Kaushik in a post Avinash wrote in October 2011. Best Social Media Metrics: Conversation, Amplification, Applause, Economic Value.
Avinash measure conversation as follows:
Conversation Rate = # of Audience Comments (or Replies) Per Post
After reading the post I was immediately reminded of a metric Stowe Boyd developed about ten years ago. Doing some searching, it was tough to find the post, Stowe doesn't have that blog running anymore, but looking back on the wayback machine I found the post from Feb 2006. The Social Scale of Social Media: The Conversational Index.
In those days social networks were not as big as today, and blogging was important, so Stowe measured the ratio of comments and trackbacks to blog posts. CI = Posts/Comments + Trackbacks.
Less than one means you had a healthy blog, achieve more than one and your blogging activities are verging on hot air, or at least an empty room.