It seems that each social media platform that reaches mass adoption does so because it successfully introduces a deeper level of intimacy than anything prior. If you think of social media, as used by organizations and celebrities, on the spectrum of "least personal" to "most personal," it would be as follows:
Facebook > Twitter > Instagram > Snapchat
I don't think it's coincidence that those companies were founded in 2004, 2006, 2010, and 2011 respectively. The most intimate is the most recent. Friendship (or fandom) on Facebook means next to nothing in 2015 – if you're not following them on Snapchat, where you get glimpses of their undoctored, minimally curated, real lives – you're not really all in.
One aspect is of what sets Snapchat apart from the other platforms is that they require a blind commitment to experience content (it's like everyone's profile is set to "private" by default). You can't see someone's snaps until you follow them, which means popularity spreads via word of mouth (which remains the most reliable and powerful method in reaching critical mass today). As a result, users are more loyal and more engaged.
Unfortunately for the world of news, where loyalty and engagement are paramount, there's no equivalent spectrum of impersonal to personal. All avenues lead back to the same level of impersonal (typically an article page on the website). While you might see a story in your feed on Facebook or Twitter, the destination of the link is still the same.
Online journalism is still struggling to find its way into the "personal" side of the media spectrum (and I don't mean recommended articles). They're missing a Snapchat equivalent – a form of raw storytelling that involves low effort, high impact user interaction and response.
In 2016 I think journalism will take a step towards filling this void by leveraging existing platforms (such as SMS, Facebook Messenger, Twitter DMs, etc) to push a hybrid of human and automated aggregation and original content to consumers for their interaction.