The Pew Research Centre found that "direct visitors" who use the news outlet's specific address or have it bookmarked stay about three times as long as those who come from a search engine or Facebook.
"Facebook and search are critical for bringing added views to individual stories, but, the data suggest it is hard to build relationships with those users," said Amy Mitchell, Pew's director of journalism research.
"For news outlets operating under the traditional model and hoping to build a loyal, paying audience, it is critical for users to think of that outlet as the first place they should turn."
The study underscores the challenges of news organisations trying to make a transition from print to digital - and keep revenues flowing.
It also suggests limits to the idea of "social news" helping traditional media organisations.
The study, in collaboration with the Knight Foundation, found a higher level of engagement from direct visitors across the full mix of sites studied.
Even sites such as Buzzfeed and NPR, which have an unusually high level of Facebook traffic, saw greater engagement from those who sought them out directly, the researchers said.
The study found it is difficult for news outlets to convert a "social" referral to a permanent direct visitor.
Of the sites examined, the percentage of direct visitors who also came to the site via Facebook was extremely small, ranging from 0.9% to 2.3%, with the exception of Buzzfeed at 11.3%.
Similarly, the percentage of direct visitors who came to a site through a search engine ranged from 1.3% to 4.1%, with one notable exception - examiner.com at 8.6%.
The researchers studied traffic using comScore data from April to June 2013 at 26 major news sites including CNN, BBC, The New York Times, Huffington Post and others.
Most people accessed the news on their computers using three methods - direct access, search or social media. But a small percentage came from other sources including e-mail, message boards and other websites.
For mobile news, Pew found the browser was used more than a dedicated mobile app, although it noted that only half of the news sites studied had such an app.