By Minal Bopaiah

Earlier this week, Re/code and The Atlantic published articles claiming Facebook was beating out Google in sending referral traffic to content sites.

Define Media Group recently debunked that myth, explaining why search traffic is still the #1 source of referral traffic for their clients, some of which include big publishers.

But perhaps you’re wondering what the best traffic sources are for subscription and paywalled sites?

According to our 2013 Online Subscription Benchmark Report, direct traffic is by far the biggest source of website traffic. But the second-biggest source is actually emails — that’s right, 47% of the subscription site executives we surveyed reported that emails were a major traffic driver, and 33% said it was a moderate source.

Search actually came in third, with 46% reporting it was a major source and 30% saying it was a moderate source of traffic.

And social media? Well, only 6% of subscription site executives said it was a major source of traffic; the overwhelming percentage (48%) said it was actually a minor source.

This data is also supported anecdotally by the numerous Case Study interviews I’ve conducted, where most digital publishers have reported that social media referral traffic rarely leads to conversion for subscription sales.