Facebook's significance as a traffic source for any website owner cannot be overstated. According to a new report by Shareaholic, who analysed the traffic of more than 200,000 websites around the globe between September 2013 and September 2014, the world's largest social network now drives more than a fifth of the overall traffic - direct traffic, social referrals, organic search, paid search, etc. - to these websites.

But not only is Facebook by far the most important source of social media traffic, it is also the fastest-growing one. In September 2014, Facebook referrals accounted for 22.4% of traffic to the sampled websites. That's an increase of more than 115% compared to September of last year, when Facebook drove 10.4% 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 recently dropped to 0.9%, down from 1.2% in September 2013. The second largest source of social media traffic is Pinterest, which accounted for 5.5% of visits to the sampled websites in September.