Content clusters implement the "hub and spoke" model. A pillar page targets the head term ("rank tracking"), and each supporting page targets a long-tail sub-topic ("how to track rankings by city", "rank tracking API"). All supporting pages link to the pillar; the pillar links back to each.
Why it works
Interlinking demonstrates topical depth. Google rewards sites that comprehensively cover a subject with higher rankings across the whole cluster, not just the pillar.
Example
A SaaS blog builds a 12-post cluster on "AI Visibility" — pillar plus 11 supporting posts. Within three months the pillar ranks in the top five for the head term, and eight supporting posts rank on page one for their long-tails.
How SEM Optimiser reports it
The cluster planner suggests missing sub-topics based on People Also Ask, related searches, and competitor coverage.
Related terms
- Topic Authority
Topic authority is a search engine's assessment of how comprehensively and expertly a site covers a subject area, influencing rankings across the whole topic.
- Content Gap
A content gap is a keyword or topic for which competitors rank but a target site does not, representing an unaddressed opportunity in the site's content strategy.
- Semantic SEO
Semantic SEO is the practice of optimising content around meaning and topical relationships rather than exact-match keyword repetition.
- People Also Ask
People Also Ask is a SERP feature that shows a list of related questions the user might also want answered, each expanding to reveal an extracted answer.