What is a topic cluster?

A topic cluster is a set of posts on various aspects or nuances of a topic, where the more nuanced posts are subtopics of the main topic.

A general structure for a topic cluster is for there to exist one or more pillar posts, several snippet posts per pillar posts, and a set of internal links between the posts in the cluster.

The image shows a hierarchy of concepts to illustrate the idea of topical authority. Pets chunks down to Dogs, Cats, Rabbits, and Snakes. Dogs further chunks down to Dachschund, German Shepard, and Pit Bull.

The image above shows an example topic cluster. In reality, in addition to links that are “up” and “down” there are links from post to post where appropriate to help readers easily move from idea to idea, but those “lateral” links are hard to show in such an image.

When did topic clusters become popular?

The idea seems to have caught on around 2017 to 2019.

Where did the idea for topic clusters come from?

Interlinked pillar posts and snippet posts were once called a “hub and spoke” model.

While the ideas of “hub and spoke” and “topic clusters” are similar, I personally consider “topic clusters” to be a more accurate and useful term. The focus is not on posts linking up and down to each other per se, but rather on posts that are topically relevant linking up and down to each other.

How do you create them?

First, you create a topical map, which is nothing more than a main topic, some sub-topics, and possibly some sub-sub-topics, which will be the titles of future blog posts.

Then you start publishing posts, with appropriate internal links between them.

What is a “topical map”?

Simply put, it’s a list of blog post subjects and topics that are topically related to each other.

What are some useful topical mapping tools?

My personal favorite is AlsoAsked, although I’m not sure why. There’s really nothing special about it, I just like it.

Other tools that produce topical maps are:

What evidence suggests topic clusters increase organic search traffic?

I personally know of no empirical studies, but many people, myself included, have created topic clusters and seen their organic search traffic increase over time.

When I search for “What evidence shows topic clusters increase organic search traffic?” most results I see talk about why they matter and how you build them.

So the best evidence is anecdotal evidence from SEOs around the world, of which there is a seemingly endless supply.

In closing

While the definitive empirical evidence topic clusters grow organic search traffic is sparse, the reports from SEOs around the world that they’ve had success with this strategy are too numerous to ignore.

Which is not surprising, considering this idea is not new, but grew from prior ideas of “hub and spoke” and “pillar posts and snippet posts”.

A lot of people have tried creating topic clusters to grow organic search traffic, and a lot of people have reported, and are reporting, success.


Kevin Carney
Kevin Carney

Kevin "fell into" SEO by accident, like many others. The SaaS platform to help writers boost their topical authority came years later after various SEOs said it was something they would like to see. https://organicgrowth.biz.

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