01
What has Google said about topics and authority?
Google uses "topic authority" in one place we found: a May 23, 2023 post about news. It described a system that "helps determine which expert sources are helpful to someone's newsy query in certain specialized topic areas, such as health, politics, or finance." That system is about news searches and news sources, not service businesses or their websites.
Google's guide to its ranking systems lists no topical authority system. Where SEO writers call it a metric, as one 2022 Search Engine Journal article put it ("a measure of authority you earn through quality content"), that's their interpretation. A "topical authority score" in a report is a tool's or an agency's own measure; Google hasn't published one.
02
Which Google guidance comes closest?
Google's guidance on creating helpful, reliable, people-first content. Its questions ask, "Does your site have a primary purpose or focus?" and whether your content shows "first-hand expertise and a depth of knowledge." It also lists a warning sign: "Are you producing lots of content on many different topics in hopes that some of it might perform well in search results?"
Google says its "automated ranking systems are designed to prioritize helpful, reliable information" made to benefit people, "and not content that's created to manipulate search engine rankings." Its helpful content system, announced in 2022, "evolved and became part of our core ranking systems" in March 2024. The guidance comes nearest to the term in another self-assessment question: if someone researched your site, would they "come away with an impression that it is well-trusted or widely-recognized as an authority on its topic?" That's an impression, not a score. Our E-E-A-T entry covers the experience and trust side of the same guidance.
03
What does subject depth look like on a contractor's site?
It looks like a site that answers the questions customers ask about the trade the business actually works in. For a roofer, that might be service pages for repair, replacement and storm damage, plus guides on materials, costs, insurance claims and warning signs, each written from jobs the company has done. That's depth on one subject, not breadth across many.
Depth also shows in the detail. A guide written from your own jobs can name the materials you install, the permits your town requires and the problems you find on real roofs, which a page written to fill a keyword list can't. Each page should also fit the search intent behind its question. The home-service SEO handbook covers which pages to build first.
04
Why doesn't publishing more pages build it?
Because Google's guidance points the other way. Its warning about producing "lots of content on many different topics" describes the volume approach, and its spam policy on scaled content abuse covers pages made in bulk with little value. Fifty thin posts on loosely related topics add pages to a site, not credibility.
A better first step is an inventory. List the questions your customers ask before they call, mark which ones your site answers well, merge pages that answer the same question, and fill the gaps with answers only someone who does the work could give. Our guide to evaluating an SEO proposal shows how to spot a plan sold by page count.
Related terms: E-E-A-T · Search intent · Domain Authority · All glossary terms
Where to go next: How to show up in Google AI Overviews covers what Google says about content that appears in its AI answers.