Millions of people flock to Twitter every day to get their news, but a new report shows that news organizations mostly use the microblogging service to promote their own stories.

The collaborative study was performed by the Pew Research Center's Project for Excellence in Journalism and the George Washington University's School of Media and Public Affairs. The two groups analyzed roughly 3,600 tweets from 13 news organizations during the week of Feb. 14 to Feb. 20, and discovered 93 percent of all tweets contained links to the organization's own site. About 6 percent of tweets had no link, 1 percent linked to another news site, and 1 percent linked to non-news content.

This behavior resembles the early days of the Web, the report said. Initially, news organizations, worried about losing audience, rarely linked to content outside their own Web domain. Now, the idea is that being a service-of providing users with what they are looking for even if it comes from someone else-carries more weight. It bears watching whether Twitter use for mainstream news organizations evolves in this same way.

Individual journalists didn't break news any more than organizations did. A study of 13 distinct journalists found that only 3 percent of tweets solicited information; yet, it makes sense that reporters would rather promote their own stories on Twitter instead of using the space to do actual reporting. While readers are likely to retweet a reporter's scoops from the site, Twitter's key limitation of 140 characters per message is far too constricting. Reporters often need more than a couple of sentences to tell the whole story accurately.

Organizations, on average, had about 41 different feeds, but varied individually. The traditional national newspapers also tended to offer the most feed-wise, with the Washington Post leading the way with 98 separate feeds, more than twice the average. The New York Times had 81 different feeds, the Wall Street Journal had 75 and CNN had 73. Only The Daily Caller, Tucker Carlson's conservative news site based in Washington D.C., was brave enough to use a single Twitter feed.

There was no consensus among the 13 news organizations in how often they tweeted. Outlets on average tweeted 33 times a day on their main feed, but that number ranged from less than 10 per day to more than 100. The Washington Post produced about 664 tweets in the sample week, while the No. 2 producer was The Huffington Post with 415 unique tweets that week.

There was only some correlation between number of tweets and follower growth. The Washington Post grew 100 percent between February and October 2011, but in that same eight month period, Fox News grew 118 percent in number of followers despite only producing an average of 48 tweets per week. The organization with the second highest activity, The Huffington Post, only grew about 49 percent during this time.

There's not enough information to conclude whether more tweets or more feeds led to more followers. The research did not calculate the average length of the organization's tweets, the time and day the messages were posted, how many times messages were retweeted or shared, and the degree to which organizations were reporting news versus breaking it. However, news organizations with a TV channel, such as Fox News and MSNBC, tended to attract more followers during the eight- month period.

Twitter, as a whole, grew strongly between November 2010 and June 2011. The report found that the percentage of online Americans using Twitter rose from 8 percent to 13 percent, a growth change of 63 percent.