Twitter co-founder Biz Stone offered some specific numbers about the service’s success and growth today while on-stage at Chirp, the first Twitter developer conference. Everyone’s been asking for these numbers, Stone said, but he explained Twitter is about people and their stories — but as he said that, the slides behind him flashed the numbers he was downplaying.

So Twitter says it has:

  • 105,779,710 registered users
  • 300,000 new users every day
  • 180 million unique visitors every month
  • 75 percent of its visitors don’t go to, but to services built by third-party developers

These numbers come from Google Analytics and an in-house data gathering tool called BirdBrain, Stone said — and when asked by conference emcee John Battelle, he added that developers will soon have access to some of the numbers from BirdBrain.