Research

How Strong Comment Communities Drive Site Traffic

Overview

Commenting has been widespread on the web for over a decade, but relatively few studies have attempted to tie commenting to tangible traffic metrics, until recently. Academic and corporate research demonstrates how active comment communities tend to drive increases in key visitor and engagement metrics from three main sources of impact:

• I. Network Cross-Pollination
• II. SEO Benefit
• III. Social Hooks

Below we share the findings from both internal and external sources.

I. Network Cross-Pollination

In 2007, a detailed University of Michigan study revealed higher commenting volume was associated with more page views, based on analysis performed on Slashdot.com¹. This summer Disqus conducted an internal analysis to evaluate whether similar results are evident across a wider sample of communities².

"The overall number of comments was relatively strongly correlated to how frequently the user requested page views." — 2007 University of Michigan Slashdot study

It was known that visitors tend to comment more over time on sites using networked commenting. In this study, a more than 4x average increase in commenting volume 90 days after migrating to Disqus reaffirmed this. Observations from Disqus Analytics and internal reporting show this lift is typically attributed to the network effects of a universal login and user profile system – the Disqus network spans over 500 million monthly unique visitors and 50 million profiles, and in addition to continuous Disqus login, publishers can allow Twitter, Facebook, Google, Yahoo, OpenID and proprietary sign-in options. Certain features and design elements that facilitate user-to-user exchanges versus just user-to-publisher response also can drive significant increases, as the most successful sites in the Disqus network have shown that a community develops best when users are able to interact at both the comment and profile levels.

Community develops best when users interact at both the comment and profile levels.

However, the primary objective was not to verify increases in comment statistics, but to understand the impact on more general traffic metrics that are measurable and can be attributed to visitor interaction with the commenting application. To this end, the analysis showed that on pages with Disqus commenting – most often news articles or blog posts – average time spent per visit increased 23%, and average page views per visit increased 13% within the first 90 days.

The blind sample used was comprised of sixteen sites, both large and small, generating more than 18 million monthly visits across a wide variety of verticals, including general news, politics, business, entertainment, technology, local and international. On average, the sites in the sample saw overall monthly unique visitors as measured by Comscore decrease by 4% over the same time period, while all sites in the sample saw at least one – and in the majority of cases all three – of the traffic metrics increase by at least 5% on pages with commenting.

The data indicate consistent and significant growth in engagement. Based on the corresponding movements between comment volume and general page traffic, a likely series of explanation is:

• A sophisticated, universal comment system frequently generates markedly large increases in comment participation due to network effects and UI design.
• The resulting increase in community activity leads to more time spent on content pages.
• More time spent leads to a higher propensity for users to navigate to other pages and/or higher odds of attracting and retaining users that interact more heavily within a given site.

II. SEO Benefit

Rewarding high-engagement content and counteracting artificial SEO lift from low quality sites is beneficial for most publishers and users. In response to growing frustration from both, Google has recently been more active in filtering out lower quality pages from search results³ . Search Engine Land developed a useful schematic for categorizing the latest factors that Google and others use to filter and rank, delineating intrinsic (on the page) and extrinsic (“off the page”) effects⁴. Networked commenting, it turns out, can have a significant impact across the ranking factors, five in particular (circled in red):

Intrinsic (on the page)

Content Words: Google’s own YouTube.com was the basis of a 2009 study from the Illinois Institute of Technology that showed that incorporating comments yielded up to a 15% improvement on search accuracy⁵ . The authors cite comment language, which often closely corresponds to relevant keywords, as the source for this boost and note a correlation between average comment length and search improvement. They point out, "on average only 34 to 58 terms are used to describe a (random) video (assuming that comments are not used to describe videos). Including the comment field in the search returns a potential richer database of information because the average number of comment terms is at least 1,485." Extrapolating this effect to any piece of published content reinforces the benefits of a robust commenting system in maximizing the amount of descriptive, crawlable content on a page. It is one of the primary reasons Disqus allows sites to synchronize comment data locally and render the text in the page HTML.

"[Comments] can improve query accuracy by nearly 15%." — 2009 Illinois Institute of Technology YouTube study

Content Engagement: As demonstrated above, an increase in commenting can lead to significant increases in average time spent. In addition to the primary engagement benefits, Search Engine Land notes: "Are people spending a relatively long time reviewing your content, in relation to similar content on other sites? That ‘time on site’ metric is another thing that search engines can measure, such as through toolbars that both Google and Bing offer."

Extrinsic (off the page)

Link Quality & Volume: It is well known that incorporating inbound links for search rank was one of the keys to Google’s success and remains one of the strongest signals of quality for all engines. As with anything, both quality and volume matter. Normally, inbound links are not very relevant for sites that use built-in comment systems, but a networked system that employs global user profiles and activity streams has a distinct advantage. In addition to the community interaction benefits previously noted, every comment generates a new inbound link back to the publisher’s page, e.g. when Seth Godin replies to a post on the Harvard Business Review. In the case of Disqus, the site’s high Google Page Rank of 8 helps these links actually mean something.

Social Shares: In addition to the default sharing on a commenter’s activity stream, commenting can facilitate sharing to the other large social platforms. As Search Engine Land describes: "If links were a way for people to ‘vote’ in favor of sites before, social media sharing is a far earlier way for that type of voting behavior to continue. Social signals are continuing to rise as an important ranking factor that search engines are using." The next section provides additional detail on the various social hooks that a sophisticated commenting engine can provide.

III. Social Hooks

Advanced systems provide a number of ways for commenting activity to gain greater presence and longevity in an average user's consumption cycle. Features like Disqus' notifications and mentions, which automatically send emails or tweets to users when a conversation is relevant to them, help promote a 'living, breathing' nature to the discussion on a page, continually pulling people back in. In addition, users can share comments or likes to platforms like Twitter and Facebook, allowing new visitors from their social graphs to see and potentially click through to the original publisher's page. Analysis across Disqus' network showed fairly strong click rates for such shared links across the board, particularly so on Twitter which many users treat as a news reader. As additional platforms like Google+ emerge, these social hooks from third party commenting systems will continue to proliferate.

Summary

With advances in next generation, networked commenting as well as search and social platforms, strong comment communities are as important as ever. Once viewed as an afterthought, mostly for increasing site "stickiness," the depth and breadth of the Cross-Pollination, SEO, and Social benefits show how commenting serves as a major driver of interaction, engagement and audience growth for sites today.

About Disqus

Disqus (dis·cuss • dĭ-skŭs') is the largest comment platform and one of the largest networks on the web, reaching over half a billion visitors each month and holding the #2 Quantcast US Rank. We are all about changing the way people think about discussion on the web. We are big believers in the communities that form on sites of all shapes and sizes, and in empowering publishers with maximum value and control.

Citations

¹Lampe, et. al., “Follow the (Slash) dot: Effects of Feedback on New Members in Online Community”, https://www.msu.edu/%7Elampecli/papers/group2005.pdf
²Disqus July 2011 traffic study on blind sample of Disqus VIP sites with pre and post-‐installation data
³"Google already knows its search sucks (and is working to fix it)," http://venturebeat.com/2011/01/12/google-search/
⁴"The Periodic Table of SEO Ranking Factors," http://searchengineland.com/seotable
⁵Yee, et. al., "Are Web User Comments Useful for Search?," http://lsdsir09.isti.cnr.it/lsdsir09-7.pdf