Twitter has 100 million active users, half of which log on to the microblogging site every day, the company said on Thursday.

About 40 percent of the users access the site mostly to read what others post, Twitter said in a blog post that seems intended to dispel the notion that many people who try it don't become regular users and that it's powered by an enthusiastic but relatively small fraction of its account holders.

It's not surprising that as it attempts to ramp up its advertising business, Twitter is providing figures that present a picture of a large and actively engaged user base. Twitter unveiled its advertising program, called Promoted Tweets, in April of last year.

The blog post also makes the point that Twitter is used by influential organizations and public figures, including 35 "global heads of state," top athletes and professional teams, important nonprofit organizations, famous entertainers and major media outlets.

This is the most recent blog post in which Twitter touts its usage, reach and clout. In July, the company disclosed that about 600,000 people sign up for a Twitter account every day, and that users send about 350 billion "tweets" daily.

In another blog post, Twitter announced that it had recently topped 1 million registered applications for its platform built by 750,000 external developers.

In recent months, Twitter has taped famous people like billionaire Richard Branson explaining why and how they use Twitter, including U.S. State Secretary Hillary Clinton, who gives Twitter an enthusiastic endorsement. Those videos are on Twitter's YouTube channel.