If one of your pages has topical authority for a keyword then it spreads to every page on your site, meaning another page can rank for it instead.
Topical authority affects a whole domain similar to link equity (PageRank).
For example, the homepage title for my SEO consulting website includes Independent SEO Consultant. The homepage is linked to from many sources with this phrase somewhere on-page. However, my page dedicated to SEO services in Salt Lake City ranks best (and well) for this query instead.
Furthermore, my SEO services page specific to SaaS ranks well for SaaS SEO Consultant. Yet it wasn’t until I discussed this subject on Search Engine Land & MarketingProfs that it began ranking mostly #1. But these sites both link to my homepage…
These backlinks help to signal the relevance of my whole site for these keywords, but a different page than directly linked to ranks best.
Here are the implications:
1. Always be including main keywords.
Keywords used across important websites (think PR & third-party review sites) help any page on your site rank better for them. Just because the backlink from their site is pointing to your homepage, which likely isn’t your best page on that topic, doesn’t mean you won’t benefit from reinforcement.
2. While direct signals are more valuable, something is better than nothing.
For the personal examples I gave, keep in mind these aren’t the most competitive queries, so the indirect benefit appears to be enough. However, even less-than-perfect SEO is helping.
Without a direct link, next best is to internally link from pages with notable, relevant backlinks to your best page.
Finally, having a good site architecture with low click depth for key pages will help.
3. Never assume search engines will rank general pages well.
Take homepages & FAQ pages for instance… Google will show the most relevant or pertinent content on your site (from their/searchers’ perspective) instead.
Returning to one of my examples, Google probably determines that many companies want SEO services from nearby vendors, so it’s ranking my SLC page to align with that intent.
Just because a general page ranks for your target keyword, even with relevant backlinks pointing to it, doesn’t mean that a more specific page won’t do far better.