While Twitter users may number in the tens of millions, only a small percentage of those create most of the content, with 5 percent accounting for 75 percent of the activity. This was found by several studies and was confirmed by social media analytics company Sysomos last month as well. But now the company set out to find out more about these 5 percent and their behavior.

“We found that 32% of all tweets made by the most active Twitter users were generated by machine bots that posted more than 150 tweets/day. The actual percentage of machine-generated tweets among the most active users is probably higher than 32% because there [are] many bots that update less than 150 times/day,” Sysomos' Alex Cheng and Mark Evans wrote.

Overall, Sysomos found that one quarter of the tweets in a day come from this type of bots but the researchers note that these bots aren't necessarily spam as most of them are coming from legitimate services like @diggupdates, @deliciousrecent, @imdb, @twitseeker and many others. Some of the most active bots, with more than 2,000 tweets per day, are @dogbook, which provides real-time updates on pet activity, and @combatsi, an update bot for the online game Second Life.

Of the most prolific 5 percent of Twitter users, 60.6 percent are from the US, followed by the UK with 6.9 percent, Japan with 4.7 percent and Canada with 4.3 percent. An interesting aspect is the gender distribution, as 54 percent of them are male; this while, overall, men make up for only 46 percent of the Twitter users. Somewhat to be expected, 48 percent of these active users have more than 100 followers.

The research firm also came up with a list of the most active users, who have over 50,000 followers, and leading the pack is the Twitter account of news TV station Fox News (@foxnews), with an average of 136 tweets per day. The second most prolific account from these popular users was that of Japanese mountain bike and BMX rider @mooris, with 109 tweets every day, followed by other individuals and organizations.