Anyone who works for a major news website or publisher knows that social referrals—that is, links that are shared on social networks such as Facebook and Twitter—have become a crucial source of incoming traffic, and have been vying with search as a source of new readers for some time. Now, according to new numbers from the traffic-analytics service Parse.ly, Facebook is no longer just vying with Google but has overtaken it by a significant amount.

1 in every 5 minutes online is spent on Facebook in the US.