This post is part three in our ongoing series on traffic sources. In part one, I talked about how we classify traffic and introduced some basic metrics for understanding the quality of traffic; in part two, we dove into some details on direct traffic. Today, I’ll talk about traffic from social sharing.

Overall, about 26% of traffic we measure comes from social sources — Facebook, Twitter, and email, for example — making social the second most significant source of traffic, next to direct. In some sense, social traffic and direct traffic represent polar opposites: Visitors who arrive via your homepage are, critically, people who intended to visit your site specifically rather than a particular piece of content. Those who come from social sources may or may not know what site they’re landing on, they’re coming because of an article that’s been recommended to them. That’s a double edged sword. On the one hand, social visitors are more likely than other visitors to actually read the pages they land on; on the other, they’re also amongst the least likely to return to your site, and when they do they’re very likely to only come via the same social channel.

Social is also categorically different than other sources of traffic because it’s the only channel that’s easily influenced — while converting visitors to come directly to your homepage is an art and affecting search engine placement leaves much to chance, we can actively choose which articles we put on social media and when to provide those links.

Demographics

Before we talk about evaluating social traffic, it’s worth discussing what sort of visitors come from social sites and how they read. First off, social sources are a better than average source of new visitors: while an average of 31% of a site’s traffic comes from new visitors (those who haven’t visited in the past 30 days), an average of 41% of social visitors are new.

Social traffic is also dramatically more mobile-based than all other traffic — an average of 25% of traffic is on mobile, but on many sites over 40% of social traffic is mobile. That should affect what stories you push to social media, and when you push them. We’ll cover both of those topics below.

Social engagement versus on-site engagement

People frequently take social media interactions as the de facto standard for “engagement” with a piece. The idea is that people who share a piece are likely to have enjoyed it. While there’s some kernel of truth here, our data suggests that there’s more to the engagement story than raw counts of tweets and likes.

Take a look at the graph below, which was first presented in Slate:

This graph shows how fully people read an article (as measured by how far down the page they scrolled; all articles shown here were over 3000 pixels high), compared to how frequently they tweet about it. If the most engaging stories to read were the stories that were most likely to be shared, we’d expect this graph to look like a line. Instead, we see that there’s essentially no correlation between the two numbers. That doesn’t mean that social interactions are a bad way to measure engagement, but it does show that social engagement and on-site engagement are often different phenomena.

Timing of social posts

So, what makes for successful social content? There’s been much written about how to write successful social posts — most recently, I read a great study by Knight fellow Sonya Song and its more concise writeup on Nieman Lab. It’s beyond the scope of this post to tackle what content to put in your social posts, but one question we’re frequently asked is what time of day is best for social sharing. Below is a chart showing how social traffic compares to overall traffic across for a set of sites (all of which are based in EST) across the past week.

Unsurprisingly, the shape of social traffic closely follows that of overall traffic, but it’s notable that social traffic substantially underperforms overall traffic from about 5am to noon, and social substantially overperforms overall traffic from about 3pm until 1am. From the perspective of driving traffic to your site, it appears that late afternoon through night is the best time to reach your readers on social media and get them to click through to your site.

Interestingly, this trend appears to be true despite people’s best efforts to the contrary. Below, we see a graph of how frequently these sites posted to Twitter, compared to their social traffic.

Posting to twitter is strong all morning and reaches its peak just before noon, even though traffic from social is actually its strongest later in the day.

Return frequency

While we’re discussing timing, it’s worth noting that visitors who come to a site from social sources do so an average of 1.5 times per week. Below we see the distribution of how many times a visitor comes from social sources across a week.

About 82% of visitors who come from social only come once, but there’s a long tail of people who come two or more times.

As mentioned above, almost 80% of visitors who come to your site from a social source will only come to your site via that source. That figure is particularly bad for visitors from Twitter, of which only about 16% will return to your site directly. These are fairly significant numbers to consider as you decide where to invest time and resources into developing your audience.

Conclusion

This post barely scratched the surface of what can be said about social media — entire companies exist to help optimize social strategy — but I hope it started you thinking about how social sharing relates to your site’s overall traffic. We’ll save further discussion of social traffic for a future post; in the meantime, stay tuned for the next post in our traffic sources series, where we’ll cover external and search traffic.

Questions? Throw them in the Comments section and I’ll respond.