Search engines have evolved, and keyword usage alone no longer guarantees you'll rank for the core services you offer. Search algorithms are now much better at determining user intent from queries - this change is so disruptive that HubSpot has changed its entire approach to boosting SEO rank to pillar pages.
Creating clusters of content that link to a comprehensive pillar page on a related core topic signals to search engines that you're an authority on that topic. That can boost your SEO rank for that subject. We're so enthusiastic about this we even built a guide on how to do it.
Keywords, however, still have a role to play. When you're choosing the core topic for your pillar page, and when you're selecting subtopics, it's best to select long-tail keywords that your domain can rank for. In this post, I'll explain how to map pillar page topics to keywords for the best SEO boost.
Research Key Metrics for Core Topic Candidates
When you start planning a pillar page campaign, the first thing you need to do is figure out some good core topic candidates - these are potential core topics that your pillar page will cover. Once you have those, it's time to do keyword research.
This is where this new approach building SEO rank with topic clusters connects with old-school keyword research - you want to find keywords that map to your core topic candidates. The best keywords will have a good monthly search volume and be relevant to your business and the personas being targeted. Beyond that, you need to define related subtopics that are extensions of the core topic.
To start, look at these metrics:
- Domain Authority: Domain Authority (DA) is a search engine ranking score which predicts how well a website will rank on search engine result pages (SERPs). Scores range from 1 to 100, with higher scores being better. To learn more see this Moz article.
- Monthly Search Volume: This is a measure of the total number of searches through search engines over a given time period, often the previous 12-months.
There are several tools that can help with this:
- Small SEO Tools Domain Authority Checker will show your domain authority for your domain, and domains you're linking to.
- Searchvolume.io tells you search volume for any keyword (Google Keyword Planner will also do this if you have an AdWords account.
- HubSpot's Content Strategy tool will tell you both Domain Authority and Search volume.
- SEMRush will tell you search volume as well, and also has a number of other features to help you find similar keywords, and to research keywords used by your competitors.
Find the Best Core Topic Keyword Combinations
Compare your core topic candidates to see which your domain ranks better for, and has higher monthly search volume. Use a robust keyword tool, such as the Google Keyword Planner or SEMRush, to help you find similar search terms. These other search terms may be more commonly used and have better monthly search volume than your original keyword candidates.

For example, if one of your core topic candidates was ‘cloud computing training,’ you may find that the term ‘cloud training’ has much higher monthly search volume.
Choose the best performing candidates to be your core topic and subtopics. Find a keyword or phrase your target audience uses regularly, and that has good search volume that your domain can rank for.
Tip: If you’re having difficulty finding core topics, identify keywords commonly used in your industry, local area, and by competitors. Refine the list to keywords that are widely used, and which illuminate the unique value your business offers or problems you solve.
Select Subtopic Keywords
Once you choose your core topic, quickly make a list of 8-22 subtopics that support the core topic. Subtopics don’t need to include the core topic words, but should include synonyms and closely-related words. For example, if the core topic is cloud training, then your subtopics might be:
- Cloud migration training
- AWS training
- Azure training
- Google cloud training
- Cloud security training
- Cloud administration training
- Cloud automation training
- Cloud adoption barriers
As with core topic keywords, you’re looking for keywords and phrases your target audience will use when searching for your products and services.
Tip: Perform analysis of monthly search volume for your subtopic keywords like you did with your core topic candidates. Subtopics with better search volume will improve traffic to your pillar page.
Perform a Competitor and General Internet Analysis
Before you finalize your core topic and subtopics, take your research a step further. Take a look at the keywords your competitors are using, and the topics they’re talking about.
Not only will this inform your final topic and subtopic selection, but it will inform you on how to position your services and differentiate yourself when you write your pillar page content.
Look for the following:
- Keywords competitors use.
- Keywords they don’t rank for but should (which provides an opportunity to rank for those keywords).
- Social channels and promotion strategies.
- Content topics.
- Competitors best performing content topics.
- Positioning and messaging.
SEMRush is an excellent tool for this. Examining how your competitors are positioning their products and services can help you refine the content plan for your pillar page. You might choose to target an underserved audience segment or accentuate a specific service or value that differentiates your brand.
In addition to looking at what your competitors are publishing, it’s a good idea to do a more general analysis of your industry, both for topics that are driving conversation and interest, and for content published on the core topics and subtopics you’re considering.
Buzzsumo can help you find this information. You can conduct your content research by typing in the core topic and subtopic candidates and see what types of articles are being shared, and which are the most popular.

Select your Core Topic and Subtopics
After all this research you’re ready to select your core topic. Choose based on your keywords, and competitor and industry research. Do the same to identify 8-22 related subtopics. At this point, you’re ready to start creating the content for your pillar page.