Only a tenth of all Twitter account holders are responsible for sending over 90 percent of all the messages sent on the site.

A new Harvard Business Review study reveals that 10 percent of Twitter users account for almost all of the activity that takes place on the micro blogging site.

“This implies that Twitter's resembles more of a one-way, one-to-many publishing service more than a two-way, peer-to-peer communication network,” said Bill Heil and Mikolaj Piskorski in the report.

“We think it also points to a large number of bored-user and spam accounts on the micro blogging service. During the All Things D conference last week, Walt Mossberg said more than half of all Twitter users return to the site less than once a month. Likewise, the HBR report says half of Twitter users tweet less than once every 74 days and that among Twitter users, the median number of lifetime tweets per user is one.

The Harvard Business Review study also revealed another interesting bit of info: men seem to follow men more than women on Twitter.

There are more women than men on twitter - approximately 55% of all users are female - but an average man will follow a man in 65% of all cases, while a woman will follow a man in 56% of cases.