Smartphones are now the leading device used to access news, while social media sites like Twitter and Facebook are much preferred sources rather than online news providers.

Online news outlets are struggling to find profit from smartphone content since people are using social media sites more than mobile news sites and apps.

Online advertising revenues are falling as smartphone users, who spend half of the time on their devices reading news, become increasingly frustrated by advertisements and so-called sponsored content, according to Reuters Institute for the Study of Journalism in its annual Digital News Report.

"Most people like news and use news, but they don't want to pay for it, don't want to see advertising around it, and don't want to see it mixed up with sponsored content. This means sustainable business models remain elusive even for those who succeed in building an audience," said RISJ Director of Research Rasmus Kleis Nielsen, according to Reuters.

The research also reports that only two-thirds of smartphone users download news apps on their smartphones, but only one-third use them on a weekly basis.

Facebook gains highest popularity as a news source, with four out of 10 smartphone users using it primarily to read, watch, share and comment on news each week. YouTube follows, then Twitter.