Joel Comm is writing a book on Twitter’s business applications and has an interesting post today in which he lays out his theory for how many people are actively using Twitter.

At the end, Joel comes to this conclusion:

Twitter Stats: “What if there are 15,000,000 Twitter accounts?

Then those with at least 1000 followers account for .03 percent.

I know. Highly unscientific.

Still, I would have to say that 1% of Twitter members create 99% of the content.”

I don’t know… just from my experience on Twitter (since Oct ’06), I’ve seen lots of people come and go, but I definitely think/feel (unscientifically) that more than 1% of Twitter users are regular users.

In my opinion, I’d put the numbers somewhere around 10% of users are creating 99% of the activity on Twitter.

However, that’s counting people interacting within the proper interface (through the Twitter.com site or through desktop clients like TweetDeck or Twhirl). If we add in sites like Facebook, FriendFeed, ping.fm, Identi.ca, etc which allow for federation and cross-posting, that number goes up to around 12 or 14%, I bet.

Just thinking off the top of my head.