SEO
Building Topic Clusters
A topic cluster is a set of pages that answer one topic together: a pillar page for the broad question, supporting pages for each sub-question, and links between them that show search engines — and readers — how it all fits.
What a cluster is, in one picture
Imagine a topic as a wheel. The hub is the pillar page: the broad, authoritative page that covers the whole topic and links out to every detail. The spokes are the supporting pages: one page per sub-question, each answering one thing completely. The rim is the internal linking that connects them all together, so a reader can move from the overview to the detail and back, and a search engine can see that the site covers the topic in depth rather than in a single page. A site built of clusters looks, to a search engine, like a site that knows its subjects. A site built of unrelated pages looks like a site that does not.
The cluster matters for two reasons. First, it concentrates authority: pages that link to each other pass relevance to each other, so the whole group rises together instead of each page fighting alone. Second, it serves the reader: a person who arrived with a broad question finds the overview, and a person who arrived with a specific question finds the detail — and each can move to the other in one click. A cluster is an SEO method and a user-experience method with the same structure, which is why it works.
The worked example: this site
The clearest way to teach clusters is to show one, and this site is built as one — no invented case study is needed. The affiliate marketing cluster is a pillar and seven spokes. The pillar is the Affiliate Marketing hub, which explains what affiliate marketing is and links to every guide in the section. The flagship spoke is How Affiliate Marketing Works, the broadest guide, which covers the model end to end. Around it sit the narrower spokes: commission models, choosing a niche, content strategy, affiliate SEO, conversion optimisation, disclosure requirements, and Amazon Associates for beginners. Each spoke answers one question completely, each links to the pillar and to the spokes it naturally follows, and the pillar links to all of them.
The same shape repeats across the site. The blogging and SEO sections form a second cluster: the start-a-blog flagship as the broad guide, with making money blogging and website monetisation as its monetisation spokes, and the SEO guides — keyword research, search intent, internal linking, technical SEO basics — as the method spokes that the blogging pages link to and that link back. The structure is deliberate: every page in the cluster links to at least three others, and every page is linked from at least three others.
Step one: pick the topic, not the keyword
A cluster starts with a topic, not with a single keyword. The topic is a subject your audience asks many questions about — broad enough to support a pillar and several spokes, narrow enough that you can cover it deeply. “Affiliate marketing” is a topic. “How affiliate marketing works” is a page. If your topic cannot fill a pillar and at least five spokes, it is not a cluster; it is a category with a few pages, and that is fine — but call it what it is, and do not force it. Our keyword research guide explains how to find the questions inside a topic, using free sources only.
Step two: map the questions into pillar and spokes
List every question the topic raises, then sort them. The broadest question — the one a beginner asks first — becomes the pillar. The narrower questions become spokes. The test is whether the spoke’s answer belongs inside the pillar or deserves its own page: if the answer takes a full page of explanation, examples and FAQs, it is a spoke. If it takes a paragraph, it is a section of the pillar. Two questions that want the same answer belong on one page; two that want different answers belong on two. That is the grouping rule from the keyword research guide, and the cluster is what the groups become once they are built.
Order the spokes by the reader’s journey, not by alphabetical order. A beginner reads the pillar, then the “how it works” spoke, then the choice spoke, then the method spokes. The cluster’s links should follow that journey, so the next step is always one click away. The same reader should be able to start at any spoke — arriving from a search — and find their way to the pillar and to the neighbouring spokes without using the site’s navigation menu. That is the practical meaning of click depth: no page in the cluster should be more than two or three clicks from the homepage, and no page should be an orphan.
Step three: write the pillar first, then the spokes
Write the pillar first, because it defines the cluster’s scope: what the topic includes, what it excludes, and how the parts relate. The pillar should be the broadest and most authoritative page in the cluster, and it should link to every spoke. Then write the spokes in the order of the reader’s journey, linking each one to the pillar and to the spokes it follows from or leads to. A spoke that does not link to the pillar is a loose page, not a cluster member. A pillar that does not link to a spoke hides that spoke from readers and from search engines.
The related-articles block at the bottom of each page is part of this structure, not decoration. On this site it carries up to six links to pages in the same cluster, so that a reader who finishes one page is offered the next step rather than the exit. Keep it to the same cluster: a related block that links everywhere links nowhere in particular, and the cluster’s signal is diluted.
Step four: link with meaning, not with repetition
Internal links carry two kinds of information: the destination and the anchor text. The destination should be the page that answers the question the reader has just formed. The anchor text should describe that destination in the reader’s words — the name of the guide, the name of the question — not “click here” and not the same keyword repeated until it is meaningless. A cluster’s links should read naturally in the sentence they sit in: “the commission models guide explains”, “the niche guide covers”. Links forced into sentences where they do not belong are worse than no links; they teach the reader to ignore links, and they teach the search engine that the site’s linking is mechanical. Our internal linking guide covers the method in full.
What a cluster must not become
A cluster fails in three familiar ways. The first is the thin cluster: a pillar and spokes that are all short, generic and interchangeable, built to look like a cluster rather than to answer questions. Search engines have seen millions of those; they do not rank. The second is the cannibalising cluster: two spokes that answer the same question in different words, competing with each other for the same query until neither ranks. The grouping rule exists to prevent exactly this. The third is the bloated cluster: spokes added because a keyword list said so, not because a reader asked, until the cluster is a pile of near-duplicate pages with nothing new to say. A cluster grows only when a new question appears that deserves its own page. If no such question exists, the cluster is finished — and a finished cluster is a good thing.
Measuring whether the cluster works
A cluster’s health can be read from three simple signals. First, the pillar’s traffic: a healthy pillar earns traffic for the broad question and sends readers onward. Second, the spokes’ traffic: each spoke should earn traffic for its own specific question, not merely borrow the pillar’s. Third, the movement between them: readers who arrive at a spoke should visit the pillar or a neighbouring spoke, because that movement is the evidence that the cluster is serving the journey rather than a single answer. If the pillar earns traffic and the spokes earn none, the spokes are not answering questions readers ask. If the spokes earn traffic and nobody visits the pillar, the links are failing. Fix the page, not the cluster: a cluster is a structure, and structures do not break — their pages do.
Last checked: 14 November 2026.