Information Architecture
September 3rd 2020

What are Topic Clusters?

12 min read

A topic cluster is multiple pieces of content grouped by a shared topic and related subtopics. As a whole, these pages offer comprehensive coverage of a specific subject. That enables visitors to satisfy their search query while visiting your site.

Your rankings are suffering, and you’re not getting the traffic you thought you would. You’ve optimized your pages using every trick in the book. You’ve gone after less competitive keywords, and still, nothing works. It feels like your content marketing strategy is stuck in the mud, wheels spinning with no forward progress.

If you’ve been publishing content based solely on individual keywords, it might be time to start thinking about topic clusters. Topic clusters are the not-so-secret weapon that content strategists are using to lay claim to high rankings in search engine results pages.

What is a Topic Cluster?

A topic cluster consists of three components:

  1. A pillar page on a core topic. This page should cover a wide range of user intents. That will give readers enough value to make them click through to the appropriate next piece of content for them no matter where they are in their buyer’s journey.
  2. “Cluster” pages that cover related topics in more depth. A cluster page tends to have a narrower focus on a specific user intent. This approach isn’t just “find a long-tail keyword and write about it.” It’s about going deep on a particular topic.
  3. Internal linking between all of the pages. Links from the cluster pages to the pillar pages are a signal to search engines that the pillar page is the most important in the group. Links from an authoritative pillar to cluster content pass authority to the rest of the cluster. Each link should also have an appropriately descriptive anchor text. This description helps search engines better understand what’s “behind” every link.

Here’s an example of a topic cluster on the topic of “Information Architecture”.

Example of a content cluster for the topic "information architecture" showing some possibilities for content clusters.

The pillar page is on that core topic – information architecture. We then have cluster content that dives deeper into specific issues under that pillar topic – topical authority and topic clusters. Of course, there would be a lot more under a cluster on information architecture, but this shows you the basic idea behind topic clusters. 

The topic cluster model also has to take into account the buyer’s journey. You’re not just creating content for the sake of it.

A diagram of the various stages of the buyer's journey showing awareness, consideration, purchase, and post-purchase.
A simplified model of the buyer’s journey. A topic cluster should have content that maps to each stage.

You want to produce a content-driven customer journey that answers questions, provides valuable information, and positions your product/service as a solution. 

One of the biggest mistakes we see people make with their content is focusing too much on one part of the funnel. Typically, it’s the bottom of the funnel. “We want people to come to our site to buy something. It’s a store, not a library,” they say.

That’s just one situation. There’s another one that’s just as dangerous.

Some marketers focus on top-of-funnel topics to get traffic, at the expense of lower volume topics. “We don’t write content for keywords that get low volume,” they say. 

Both approaches take you away from the topic cluster model. You need to cover the entire funnel with content, creating a complete customer journey. The buyer’s journey is nonlinear, so you want to cover as much ground within a topic as possible to ensure that no matter where someone is in their decision process, you have content for them. 

Not everyone who reads your content is going to be a customer, and that’s OK. You want to serve information-seekers as well as people who are ready to buy. In fact, it’s almost impossible to rank for purchase intent keywords unless you have the authority on your topics to surround your product pages. 

A website without a blog is an online brochure, one with very low domain authority and rankings

Why You Should Consider Topic Clusters

Since the introduction of Google Hummingbird in 2013, content marketing has fundamentally changed. Gone is the emphasis on keywords and pages. In its place, we have pillar pages, content clusters, and subtopics. All this combines to create websites with high topical authority. It’s the type that Google favors.

Before Hummingbird, inbound marketing was relatively simple. The typical content strategy consisted of finding popular search queries. Then you would create blog posts to match each of those keyword phrases.

Each page was optimized to rank for a specific keyword. The intense focus at the page level meant little attention was paid to the site as a whole.

Eventually, large sites found themselves with many pages of similar content. They were targeting so many keywords they couldn’t keep track! The unique content tended to be shallow. They lacked the depth necessary to satisfy search intent for any particular topic.

It’s what content marketers often refer to as ‘thin content.’

Search engines are getting better at determining expertise. So smart content strategists are shifting the focus from keywords to topic clusters. They’re using topic clusters to organize their content and build authority.

In the current environment, a content plan that does not use this tactic is at a severe disadvantage. It’s too difficult for low authority sites to achieve meaningful rankings. To give you an idea of how a plan would look, here’s a post on building a content plan with topic clusters .

Now to be fair, topic clusters aren’t exactly new. In fact, WordPress users are familiar with a related concept known as ‘category.’

Categories and topic clusters are very similar. While every category is a topic cluster, every topic cluster is not necessarily a category. For example, on a website that sells appliances, we may choose to make a category for ‘kitchen appliances,’ while keeping blenders and food processors as clusters.

There are no hard and fast rules when it comes to organizing a website using topic clusters. Usually, a group will have at least four pieces of content, but that’s a suggestion. Your content plan may call for multiple items of content in a topic cluster. But you can publish them one at a time according to your schedule.

Existing sites can also take advantage of topic clusters. To restructure an existing site, you’ll first need to conduct a content audit. List every blog post and group entries into topics and subtopics. Eventually, you’ll end up with clusters of content which you will link together at a later stage.

The SEO Impact of Topic Clustering

Correctly implemented, topic clusters can have a significant impact on SEO results in two ways. First, there’s an increase in site authority and overall page ranking that is conferred to sites that comprehensively cover their chosen topic(s).

Although we’re just speculating, it does make sense. Google’s stated intent is to provide relevant results that match search intent—making use of topic clusters to thoroughly cover a subject tips the odds of achieving a high ranking in your favor.

But really, it’s not speculation. At a minimum, internal linking helps distribute PageRank thus improving the SERP performance of pages that might otherwise not do as well.

More obvious is the type of results we’ll see when we look at the examples below. Sites with well organized and large topic clusters are more likely to receive enhanced listings.

Consequently, on-page SEO efforts are becoming increasingly more important. That’s good news for both you and your audience! In fact, the focus on improving user experience is widely recognized as an essential SEO strategy.

Topic clusters are useful regardless of your site’s size. If you want your site to grow, get started using topic clusters today. Keep in mind that the impact of content organization increases with the amount of onsite content. In theory, more content means greater possible coverage of a topic. This assumes that each post is, in fact, in-depth content.

Creating topic clusters isn’t tricky. Covering all of the possible user intents as are relevant to your business is undoubtedly a lot of work, but executing based on the framework we’ve described above isn’t above the talents of a determined content marketer.

Real-world Topic Clusters

So far, the conversation has all been theoretical. Let’s look at some real-life cases to see how others work topic clusters into their content strategy.

B2B Topic Cluster Example

A great example of a B2B content cluster is Gremlin’s topic cluster on chaos engineering

It starts with this nicely designed pillar page that is a complete introduction to chaos engineering. It covers the history, principles, and specific things chaos engineers do. It’s well-structured and easy-to-scan, making it ideal for both search engines and humans!

From there, it links out to cluster pages that point readers to in-depth pages on the topics they discuss at a high-level in the pillar page, such as:

screen shot of pillar page on gremlin.com

At the top of the funnel, particularly on the pillar page, we can see that Gremlin isn’t bombarding us with links to product pages or demo form fills. The next step from the pillar is clearly to dive deeper into the informational side of chaos engineering. There are also several links to join the chaos engineering community run by Gremlin.

Use this tactic to lead users, just starting to learn about the concepts and topics relevant to your products and business, to consider your solution. Likewise, Gremlin has lots of content on specific chaos engineering workflows and solutions for people who are past that initial Awareness phase and want to vet a solution, not read informational articles. 

B2C Topic Cluster Example

Most examples of topic clusters come from the B2B space, but it’s equally effective in the B2C arena. PC Gamer is a perfect example here.

Their guide to building a gaming PC is textbook pillar content. It covers all of the relevant parts you need a build gaming PC – GPU, motherboard, storage, cases, components, etc. It also recommends specific products for each part of the build.

Screenshot of a gaming PC build guide.
An example of text-book pillar content.

The page also has a robust internal linking structure to other guides and related content (such as PC games), so users who aren’t ready to buy have more information they can get without leaving the site. The core pillar page points to other PC building guides that each target a unique buyer persona, from someone looking for a cheap PC build to an “extreme” one.

Getting Started With Topic Clusters

Topic clusters can be powerful when implemented correctly. Start small and focus on producing quality content. Organize your existing content and look for potential pillar pages. Improve those as required, and link it all together. 

Then move onto creating topic clusters as part of your regular publishing activities. Soon, you’ll have a content hub with high-quality, organized content that makes it easy for users and search engines alike to find your content.

If you’re wondering, “what impact can this really have for me?” – we’ve got you. Check out this case study where our friends at Yello used MarketMuse to build an authoritative content cluster that drove organic traffic success, elevating their brand profile for the long haul. 

Stephen Jeske

Written by Stephen Jeske stephenjeske