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.

Heavy-duty Twits, er, Twitter users see none of this as surprising. These folks apparently enjoy being led around by the usual cryptic 140-character messages and truncated links that are the Twitter experience. They are Twitter viewers, using service, typically through a Twitter app, to watch but not really contribute.

The study explains why people like myself, who would rather interact with people they know find Twitter fairly vapid. I really don't need to find out what some cyber celebrity is eating for lunch or thinks in funny at the moment. On the other hand, there are some news sources that have my attention, just like on TV.

That doesn't mean Twitter can't be useful and I am not going to throw the TweetDeck client I use into the trash, but the study explains how Twitter and truly interactive networks, like Facebook, are fundamentally different. Something Facebook doesn't seem to understand.

All this can change, of course, if more Twitter users were to start tweeting more often. However, the short message limitation and meaningless URLs make Twitter a challenge for new users. And a frustration for those who actually have something to say.

As long as Twitter mostly consists of people sending links with short descriptions attached, it will never be truly interactive. That's not bad thing, we should just calibrate our expectations accordingly.

David Coursey tweets more often than the median user. Write him using the form at www.coursey.com/contact.