No, it's not a birthday milestone, but 100 million is the number of active users according to a recent Twitter announcement.

100 million is a big number but if you dig a little deeper the headline number starts to reduce.  There is no hard a fast rule on the definition of an 'active' user but in anyone's money you might argue it means daily or (I'm being generous) weekly use.  Twitters definition of active is an account used at least once per month; no really, it is!

They have around 50 million daily users -- which is a more accurate measure but doesn't have the same headline impact.

For the stats junkies, a few more:

  • 200m registered accounts
  • 100m user twitter at least once per month
  • 50m every day
  • 55m use a mobile device at least once per month
  • 230m tweets per day
  • 8,900 tweets a second

All interesting stuff, especially when you consider Twitter are looking at new ways to slot in advertising and therefore sell advertising space.

Hopefully they can start investing more in infrastructure!  I find Twitter searching to be a bit hit or miss and the  message that "Twitter is over capacity" irritating.  I've never seen such a regular  message on any other mega-web services.

site by DAJ