Dive summary: 

• As certain browsers continue to block websites from tracking how their users landed on a page, the problem of "dark search" or "dark Google" arises. 
• When certain browsers can't be tracked, the numbers of search traffic drops and direct referrals from social media seems to rise. 
• Digital agency Rosetta claims that the biggest causes of dark search are users operating iOS 6, which runs on iPhones, iPads and iPods, as well as users of recent Firefox editions. 

From the article: 

"Many publishers and marketers are looking at this inaccurate and incomplete data and drawing conclusions based on it. Buzzfeed, for example, published a story this week citing aggregate data from 200 publishers in its 'Buzzfeed Network.' In the last eight months, traffic from Google to its partners’ sites has dropped 30 percent, it said, while referrals from Facebook continue to rise. It implied this shift is indicative of a 'shift in the way readers discover their content.' Perhaps in part it is, but it’s also likely that dark Google played a far more significant role."