How Mainstream Media Outlets Use Twitter
Use of Hashtags
There is also wide variation in the use of hashtags by the news organizations studied. The hashtag symbol (#) is used before key words to categorize tweets and helps facilitate searches within Twitter. Clicking on a hashtag will show all the tweets in a category. There was significant variation in the use of hashtags across the news organizations examined, suggesting significant variation in the extent to which these organizations utilize the unique aspects of this tool.
The Washington Post, one of the most active news organizations studied on Twitter, regularly used hashtags (21% of tweets studied included at least one hashtag) to categorize tweets. Fox News and the two local newspapers, The Toledo Blade and The Arizona Republic, used hashtags even more. By contrast, some outlets, including those that had a high volume of tweets like The New York Times and NPR, almost never used hashtags. In the news context, hashtags signal that a tweet (and by extension the linked story) are related to a particular ongoing news story or topic. Given the promotional function that Twitter appears to serve for news outlets, the lack of hashtag usage is perhaps surprising as hashtags would enhance the chance that a news organization's stories will be read by individuals who are not already following their feed.
A closer look at the nature of hashtag use signals variation as well. Sometimes hashtags themselves are used in promotional ways, such as when CNN uses the #CNN hashtag within tweets. The data show, however, that many hashtags were used to connect a single tweet to an ongoing news story.
For example, there was considerable use of country-based hashtags (#Bahrain, #Egypt, #Yemen) to connect tweets to the ongoing events of the Arab spring in February 2011. For news organizations using hashtags in this way, they are linking their content into a larger conversation about the topic on Twitter. The Daily Caller-an outlet with a high proportion of conservative content-had the highest proportion of tweets with a hashtag of all the organizations examined. A closer look at these tweets shows repeated use of #TCOT and #GOP-hashtags which might help link information from the Daily Caller into politically conservative social networks.
 "Non-Profit News: Assessing a New Landscape in Journalism." Project for Excellence in Journalism. July 18, 2011.