27% of Twitter accounts posted at least one public message between September 1st 2011 and November 30th, according to a study released by Semicast. This means that many Twitter users mostly use the service to read tweets from others.
The most active country on Twitter is the Netherlards, where 33% of accounts posted at least one public message. In second place comes Japan, while Spain is the third with 29%. This data comes from analyzing 383 million of Twitter user profiles created before January 1st 2012.
Drawing from its experience with previous studies, Semiocast used its proprietary platform, databases and tools to process user profiles in order to determine the location of each user using all available information (free-form location declared in user profile, time zone, language used to post tweets and GPS coordinates for the very few concerned tweets).