BARELY a tweet is heard from most Twitter members despite the soaring popularity of the micro-blogging service, according to a pair of freshly-released reports..

Web analytics firm HubSpot found that nearly 55 per cent of 4.5 million Twitter members monitored have never “tweeted” — fired off concise text messages to others using the micro-blogging service.

More than half of Twitter members have no followers and about 55 per cent of them aren’t following anyone else’s micro-messages, according to a “State of the Twittersphere” report by HubSpot.

Meanwhile, a study by Harvard Business School researchers concluded that 10 per cent of Twitter members account for 90 per cent of tweets.

“A typical Twitter user contributes very rarely,” Harvard MBA student Bill Heil and assistant professor Mikolaj Piskorski said in a university blog post containing the findings.

“Among Twitter users, the median number of lifetime tweets per user is one.”

Those that do tweet tend to do so during traditional US work hours, with messaging dipping on weekends, according to HubSpot.

Common phrases used in tweets indicate the San Francisco startup’s service is most popular in cities where the dominant language is English, said HubSpot, which noted that Twitter continued to grow at “an astounding” rate.

Twitter has been adding millions of users a month and its website received 32.1 million unique visitors in April, according to tracking firm comScore.

Twitter, which allows members to exchange 140-character-or less messages, can be used on computers, mobile telephones, and now on television sets using a newly-announced online link to Microsoft Xbox 360 videogame consoles.