Facebook's significance as a traffic source for online publishers cannot be overstated. According to a new report by Shareaholic, who analysed the traffic composition of more than 200,000 websites around the globe between June 2013 and June 2014, the world's largest social network now drives almost a quarter of the overall traffic to these websites. But not only is Facebook by far the most important source of social referrals, it is also the fastest-growing one. In June 2014, Facebook referrals accounted for 23.4% of traffic to the sampled websites. That's an increase of more than 150% compared to June 2013, when Facebook drove less than 10% of traffic.

Twitter's role as a traffic source pales when compared to its larger rival Facebook. The share of traffic driven by Twitter referrals has fluctuated around 1% for the past year and does not make any signs of changing in either direction. Aside from the obvious difference in size, Shareaholic attributes Twitter's comparably minor role in traffic generation to a couple of reasons: one being the assumption that the Twitter feed is less personal than Facebook's news feed is, and that links posted in Tweets are therefore less relevant to users. Another one being the idea that brands tend to use Twitter as a brand building tool, rather than a means for traffic acquisition.