New Harvard Business research data seems to prove something many had already figured out: Twitter is a broadcast medium, not a conversation. So how is an essentially one-way conversation considered to be a social network? Does that standard also make television and radio into social networks, too?

Across the 300,000 users studied, the median number of lifetime Tweets is one. That means half of Twitter users tweet once every 74 days. Which is also about the churn rate for new Twitter users, many of whom quickly leave the service. Seemingly after tweeting only once.

On the other hand, the top 10 percent of Twitter users are responsible for 90 percent of all tweets. If that isn't broadcasting, I don’t know what is. Twitter would be better served if maybe half of users were responsible for the same number of tweets.

More: http://pcworld.com/businesscenter/article/166118/