Hitwise says web visits have increased 8x in the last year, albeit from a minuscule base. Compete shows about 900,000 U.S. monthly website visitors. Comscore puts the worldwide number at 1.3 million unique monthly visitors in March.
None of that data is particularly useful, since so much of the action on Twitter occurs via mobile phones, instant messaging and desktop clients like Alert Thingy, MySocial24x7 and Twhirl. Many of Twitter’s most active users rarely visit the website.
The key measure of Twitter usage is total users, total active users and total messages sent. And according to a source close to the company, these are the current Twitter usage stats:
Total Users: 1+ million
Total Active Users: 200,000 per week
Total Twitter Messages: 3 million/day
Note: It’s not clear what the 1 million total users refers to, since there are many more registered users (see comments below). It may be users who’ve left at least one message, or an active user number that is over a longer period than the weekly number (monthly, for example). Those stats have roughly doubled just since January, when Twitter had just 100,000 active weekly users. Previously it took nine months to double in size – In April 2007 the service had 50,000 active weekly users. What’s most interesting is the rabid Twitter usage by active users – they send an average of 15 Twitter message per day.
The company has not blessed these numbers, nor do I expect them to. If they respond to my email request for comment I’ll post an update here.
Update: Twitter declined to comment.
Update 2: Peter Kafka at Silicon Alley Insider adds another interesting stat. There are 4 million connections between Twitter users (Twitterers following other Twitterers, with some duplication obviously), based on a slightly higher number of 1.3 million total users three weeks ago.