Topic cluster

A topic cluster is one thorough page on a subject, surrounded by several narrower pages that each handle one part of it, with links running between them. The broad page is usually called the pillar. The narrower ones are the cluster. Arranged this way the pages stop competing with each other, each one is easier to reach, and the set reads as coverage of a subject rather than as scattered mentions of it. That is most of what makes a group of pages worth more than the same pages published at random.

In short

• A cluster is one broad pillar page plus several specific pages, linked to each other.
• It exists to stop your own pages competing for the same search.
• The links are the mechanism, not the folder structure and not the category tag.
• Most sites can build their first cluster out of pages they already have.

The three parts

There is nothing complicated in the shape. The discipline is in holding to it.

• The pillar. A page covering the whole subject at a useful depth, summarising each part in a few paragraphs rather than exhausting it. Written for the broad search.
• The cluster pages. One page for each genuinely separate question underneath the subject, each going properly deep on its own question and no further.
• The links. Every cluster page links up to the pillar. The pillar links down to every cluster page. Cluster pages link across to each other where a reader would actually want the jump.

If any of the three is missing it is not a cluster. A pillar with no links is a long article. Cluster pages with no pillar are a pile of posts.

The problem it solves

Clusters are not a growth tactic. They are a fix for a specific failure that almost every site develops with age.

• Keyword cannibalisation. Three of your own pages half answer the same search, so a search engine has to pick, splits the signals between them and frequently ranks none of them well.
• Pages nobody links to. Posts published and never referenced again, reachable only from an archive nobody visits.
• Depth spread too thin. Six shallow pages on one subject look weaker than one thorough page, and they were more work.
• No route through the site. A reader who wants the next step has to go back to search for it.

The cluster answers each of these by deciding in advance what each page is for and then wiring the set together.

Choosing the pillar

The pillar should be something you want to be known for, and broad enough that narrower questions genuinely sit underneath it.

• Take it from what you sell, not from what happens to have search volume. A cluster around a service you do not offer is a hobby.
• Check it is actually broad. If you cannot list four separate questions underneath it, it is a cluster page, not a pillar.
• Look at the results page first. A SERP analysis will show whether the broad search wants a comprehensive page at all, or whether it is owned by directories.
• Expect it to be slower. Broad pages take longer to rank, and the cluster pages underneath often bring in inquiries first.

Deciding what becomes a page

This is the judgement that decides whether the structure helps or bloats.

• Would somebody search for this on its own? If yes, it is a page. If it is only ever asked as part of the bigger question, it is a section.
• Is there enough to say? Enough to answer properly, with specifics. If not, it belongs inside the pillar.
• Does it overlap an existing page? If it does, improve that page instead of adding a competitor to your own site.
• Does it have a different intent? A page for somebody comparing options and a page for somebody ready to buy are two pages even when the subject is identical.

The failure mode here is splitting for the sake of the diagram. Ten pages that each say a third of something are worse than three that each say all of it.

Linking the cluster together

The links carry the whole structure, so they deserve more thought than they usually get.

• Link inside the content, in the sentence where the subject comes up, rather than in a related posts strip at the foot.
• Describe the destination in the link text, since the words a link is wrapped around are part of how the target page is understood. This is basic on-page SEO.
• Keep the pillar linking to every cluster page. When a new one is published, the pillar is edited the same day or the cluster quietly stops being one.
• Link across, not only up and down, where a reader would benefit.
• Do not link everything to everything. A page whose body points at every other page has effectively signalled nothing about any of them.

What one looks like for a small business

The examples usually given involve publishers with hundreds of posts. The version that matters here is smaller and mostly consists of pages a business already needs.

A service business might have a thorough page for a service as the pillar, then separate pages for the questions customers ask before booking it: what it costs them in time, what happens on the day, what they need to prepare, how it differs from the cheaper alternative, and what it looks like in the specific areas served. Each is a real page answering a real question, and each links back to the service.

That is a cluster, and it is also just a well organised site. Deciding which of those pages to write first is a content marketing question. The overlap with information architecture is not a coincidence: both are about deciding what deserves a page before anybody starts writing.

Where clusters go wrong

• Publishing the cluster pages and never writing the pillar, which leaves a set of pages with no centre.
• Writing the pillar as a summary of the cluster pages, so it says nothing the others do not and gives nobody a reason to read it.
• Padding to a number. Twelve pages because twelve was in the plan.
• Forgetting the links at publishing time, which is the most common failure and the easiest to prevent with a checklist.
• Never revisiting it. Clusters age. Questions customers stopped asking should be merged away, and questions they started asking should be added.
• Treating it as a filing system. The point is coverage and connection, not tidiness.