Google has strived for years to diversify search results. Yet it still frequently returns two or more organic listings per query from the same site, which search optimizers call “domain clustering.”
On desktop results, the second clustered listing is indented.
But it’s not indented on mobile.
Having two listings for a single query presumably produces more clicks. Thus optimizers sometimes seek ways to achieve those results. I know of no documentation from Google on the topic. But anecdotally it appears Google uses clustering in three scenarios.
Dual meanings. A keyword query could have dual meanings, prompting Google to produce a listing for both. An example is a query for “framing.”
Unsure of intent. Google may cluster results when it’s uncertain of the searcher’s intent — commercial or informational. An example is a search for “french drain.”
Similar URLs. A website could have multiple relevant pages for a single query, such as similar products or categories. Google could deliver two or more of those pages to help the searcher. Target, for example, offers “floating wall shelves” and “wood floating shelves.” Thus Google has clustered both URLs for the query “floating shelves.”
In other words, Google continues to cluster domains when it helps searchers, despite announcing search-result diversification in 2019.
But optimizing keywords for clusters risks one page competing against another.
“Keyword cannibalization” means optimizing two or more pages of a site for the same search term. It’s a dubious tactic for two reasons.
First, it could confuse Google’s algorithms, unsure which page to index and rank. And confusing Google is bad. I have often seen informational blog pages rank where the searcher’s intent is clearly commercial.
Second, the practice splits keyword equity between multiple pages, diluting them and thus “cannibalizing” SEO efforts.
For years, I’ve monitored keyword cannibalization in SEO audits. Sites with high-ranking pages avoid it. Thus a logical question is how to optimize for domain clustering without cannibalizing keywords.
One option is “intent optimization.”
A site can optimize for searchers’ intent, not just their keywords. There’s nothing wrong with creating two pages for the same topic: one for commercial intent and the other for informational.
For example, a search for “tile paint” could apply to buying paint or using it. Hence optimizing for that query would include a product category page with multiple purchase options and an informational guide or article.
The pages should link to each other to address searchers’ needs. Keywords for purchasing could include “on sale,” “easy to use,” and similar, whereas informational terms might be “how to” and “common mistakes.”
Creating seasonal how-to guides to supplement commercial pages can help with domain clustering. The guides could list gift and costume ideas and decor options, as examples.
Regardless, optimizing for clustered domains risks keyword cannibalization. I would not attempt it for a page already ranking at or near the top for a target keyword. Plus, clustered results come at a price: they seldom appear for position 1.