What Are Topic Clusters And Why Are They Important For SEO?

Did you know that 78% of marketers believe their content marketing was successful because they had a documented content marketing strategy? This means that you can’t just create content for content sake. Your content marketing strategy relies on purpose and must provide value to users and serve search engines. 

In 2013, Google began its journey in understanding semantic search terms through the Penguin update, which was then followed by a series of other algorithm updates for continued improvement. Notably, the RankBrain and BERT updates in 2015 and 2019 helped Google comprehend search queries and serve web pages that satisfy user intent but, that’s not to say the work is done for marketers! We still have a responsibility to make Google’s job easier and help crawlers understand our content. This is where topic clusters come into play. 

• What is a topic cluster?
• What are the benefits of topic clusters for SEO?
• How can you use existing content to build topic clusters for SEO?
• Step-by-step guide to creating topic clusters for your website
• Final thoughts

What is a topic cluster?

An SEO topic cluster refers to a group of related pieces of content that are linked together using hyperlinks, and that link to one hero content piece, or pillar page. When looked at as a whole, these content clusters provide a comprehensive view of a larger topic, and each individual piece offers a deep dive into more specific subtopics. 

There are three components to a topic cluster:

• A pillar page, typically targeting short-tail keywords and covering a core topic.
• A selection of smaller content pieces (cluster pages), targeting niche topics and long-tail keywords.
• Internal links to and from pillar and cluster pages.

Here’s a topic cluster example to help you visualise the concept…

And, this is what it would look like site-wide:

What are the benefits of topic clusters for SEO?

There are many benefits to creating topic clusters, both for SEO purposes and for improved user experience. Here are just some of the key benefits of topic clusters…

• Streamline site structure

Topic clusters are helpful to search engines, like Google, and aid them in finding your content more easily through efficient internal linking.

• Increase ranking positions

According to experiments run by HubSpot, an increase in links between related content contributed to improved positions in the search engine results pages (SERPs) and increased impressions. 

• Build authority and dominate your niche

Topic clusters link together and help Google understand the relationship between pages and if Google sees that your site is creating lots of related content on one topic, it will regard you as more of an authoritative voice in the space. This will help boost your E-A-T signals to Google and improve your search rankings, which is also known as a semantic SEO strategy.

To help boost authority further, you can incorporate an off-site SEO strategy to build backlinks to your cluster content.

• Increase time on site and reduce bounce rate

Adding internal links from one content piece to another will keep users on your site for longer, reducing bounce rate and signalling to search engines that your site provides value. 

• Enhance user experience 

Topic clusters offer users a comprehensive answer to their questions, providing a large library of information around related topics and serving their search intent. It could even answer questions they didn’t know they had!

• Grow the top and bottom of the funnel

Creating topic clusters can help you grow the top of the marketing funnel, at the awareness stage, bringing more visitors to your site organically – who will hopefully make their way through the funnel to conversion. Likewise, you can leverage pillar pages as landing pages, providing users with valuable content in exchange for personal details and email addresses. According to HubSpot, 90% of people prefer downloading a PDF rather than reading long-form content on a web page, so it’s important to use this to your advantage.

• Improve content production efficiency

Creating content around related topics will enable you to produce content for your site much more efficiently. Once you’ve done the bulk of the research for your pillar content, cluster content will be much easier and quicker to write.

• Increase revenue

Creating a content cluster centred around a transactional page or a web page that generates a lot of revenue will lead website visitors to your sales pages and bring them closer to conversion. And, with content marketing already having the potential to deliver a significant return on investment, this is sure to get your decision-makers on board.

How can you use existing content to build topic clusters for SEO?

Before you begin creating new topic clusters, it can be useful (and time-saving) to look through the existing content on your site. A lot of the time, you will have some existing material to work with and repurpose for your topic clusters. This should be a natural part of your content auditing process. 

In some instances, it will simply be a case of adding some additional internal links to your pages or creating a tailored pillar page to link towards. You may also find that some content is not useful or overlaps with others, and can be eliminated or merged with other content on your site.

Sieving through your existing content prior to building a topic cluster is also beneficial to ensure you do not create duplicate content unnecessarily!

Step-by-step guide to creating topic clusters for your website

Now you understand what a topic cluster is and how it can benefit your website, it’s time to get into the nitty-gritty of how to create your own topic clusters.

1. Pick a central topic

The first step to creating your topic cluster is to pick a topic, which may not always be as simple as it seems. There are a few questions you need to ask yourself when choosing a central topic for your cluster:

• Is it relevant? 
• Is it too broad?
• Is it too narrow?
• Does it have sufficient search volume?
• Will it generate a high volume of traffic?
• Does it satisfy user intent?

You need to make sure that you are choosing a relevant topic that will resonate with your target audience, without being too broad or too narrow. One way to determine this is to use an online keyword research tool, like Ahrefs, and take a look at how many keyword ideas it has, as well as the search volume and traffic potential. 

2. Conduct keyword research

Next, it’s time to go more granular. In-depth keyword research is essential to help you identify which topics will enable you to improve your search rankings and generate the most traffic to your website. There are a number of online tools you can use to do this, such as Ahrefs’s keyword explorer and Semrush’s keyword magic tool. 

Let’s take a look at ‘lawn care’ for example. This has a global search volume of 86k, which means it has high search volume and excellent traffic potential. Ahrefs can also help you identify cluster topics by clicking on the ‘parent topics’ tab. In this instance, this could be a lawn care calendar, winter lawn care, lawn care equipment or lawn care for different months of the year. These tend to have much lower search volumes and target longer-tail keywords.

Rule of thumb: choose keywords with a hard to medium ranking difficulty for your pillar pages and keywords with lower search volume and low difficulty for your cluster pages. You can find this information using Ahrefs.

Ahrefs will also show you an estimate of how many backlinks you need to help your pillar pages rank in the top 10 positions in the SERPs, and we recommend using this to inform your off-site SEO strategy. 

3. Make sure your clusters cover all bases

After taking a look at keywords, we recommend doing some more research to make sure you haven’t missed anything. You want to ensure that your clusters are answering all your audience’s questions and leaving no gaps!

Answer the Public is a fantastic tool for this, giving you a visualisation of all the possible search queries related to your central topic. This is broken down into the who, what, where, when, how and much more. Here’s an example for ‘lawn care’:

It may also be worth your while doing some manual research, looking at the people also ask section in the Google search results,or seeing what comes up on Google’s autocomplete tool.

It is likely that you will find some overlap between these topics and your keyword research, so make sure to prune where appropriate.

And, it goes without saying, that you should always keep your target persona in mind and create audience-first content. You may need to conduct some social listening or create detailed buyer personas to inform your tone of voice and blog messaging. 

4. Map out the topic cluster structure

Planning is everything. So, next, you will need to map out your clusters and decide what pages you will interlink. You can either do this in a simple spreadsheet, use a cluster planning tool, like Frase topic planner or HubSpot’s Strategy Tool, or an online brainstorming tool, like miro. 

The basic outline of a topic cluster could look something like this:

5. Flesh out your pillar page

Now that you’ve done all your research and have a clear idea of the types of content you will be writing, it’s time to create your pillar page. In some cases, your pillar page will be a key transactional page where users will convert, such as a product or service page – like grass seed in the example above. If this is the case, you will need to make sure it’s full of compelling imagery of your products, and a balance between sales-focused messaging and valuable information to help users make the decision to convert. It could even link to additional resources to provide the final bits of information to inform their decision. 

However, a pillar page doesn’t have to be a transactional page. It could be a longer-form article or e-book, that broadly covers an overarching content theme. It is recommended that a pillar page is more than 3000 words, however, above all, it must provide value to the reader.

Since pillar pages are typically long-form, we recommend including a table of content with internal jump links to help readers navigate the page and consume the content they want. 

6. Write amazing content clusters

Following on from your pillar page, you can then start writing cluster content, making it as informative as possible and delving deep into each subtopic. You should follow the usual best practices for SEO and content writing. 

Remember to link back to your pillar page, and between cluster pages where relevant, to show search engines the relationship between your content.

Some people may choose to switch steps 5 and 6 around and create cluster content first, in order to avoid duplication between the content pieces.

7. Measure your success

Just like any other SEO strategy, it’s key to measure your success on an ongoing basis so that you can learn from your findings and guide your strategy moving forward. It may take a couple of months to see traction from a topic cluster strategy, as rankings can take a while to pick up and the SERPs are always changing. Here are some of the ways you can measure the performance of your topic clusters using Google Analytics:

• Improvements in rankings for your pillar page and cluster content
• Increase in site traffic to your pillar page and cluster content
• Boost in conversions on your pillar page e.g. sales or email sign-ups
• Reduced bounce rate site-wide
• Increase time on site

We recommend carrying out a content audit regularly to check on progress, especially in the aftermath of any Google algorithm updates!

Final thoughts

Topic clusters are a proven strategy to boost your SEO results, especially as Google continues to improve its understanding of semantic relevance between web pages to serve users with the best possible content. Follow our step-by-step guide and see results for yourself.

If you’re looking to streamline your content strategy and boost your site performance, check out our content marketing services or get in touch with our team.