How internal linking works
An internal link is any link from one page on your site to another. It does two jobs at once. For a visitor it is a route: a way to move from a question to the answer, or from a guide to the service the guide describes. For a search engine it is both a discovery path and a recommendation — a page that many of your own pages link to is being flagged, by you, as one of the important ones.
Some of that value travels through the words in the link. The visible anchor text tells a search engine what the destination is about, which is why a link reading “Google Ads audit” is worth more to the target page than one reading “here”. Position matters too: a link inside the body of a page, surrounded by related writing, carries more weight than the same link repeated in the footer of every page on the site.
Why internal linking matters
It is the one ranking factor you control completely. You cannot decide who links to you from outside, but you decide, today, which of your pages get supported. When a service page is not ranking, the cheapest available fix is usually to link to it properly from the pages that already earn traffic, rather than to write anything new.
It also shapes how a search engine understands your site. A set of related pages that link to each other reads as coverage of a topic rather than as scattered articles, which is what makes a group of pages rank as a group. And it does plain commercial work: a reader who finishes an article and finds a relevant next step is far more likely to enquire than one who reaches the bottom and stops.
Common mistakes with internal linking
The most damaging is neglect. Pages get published, nothing links to them, and they become orphan pages reachable only from the sitemap. They are crawled rarely, understood poorly and rank accordingly.
The opposite failure is volume without thought — every other sentence linked, mostly to the same handful of pages, with anchors like “this page” or “learn more” that describe nothing. Menus and footers are also mistaken for internal linking; they link every page equally, so they distinguish nothing. Two more worth checking: links that pass through a redirect instead of landing on the final address, and deep pages buried so many clicks from the homepage that neither visitors nor crawlers reach them.
How to act on it
Decide first which pages are supposed to earn money, then work backwards. List the pages that already receive traffic, read them, and add a link to a money page wherever the sentence genuinely calls for one. That single pass usually finds more opportunities than any tool.
Keep the anchors descriptive and varied: describe the destination in the words a reader would use to search for it, rather than repeating one exact phrase everywhere. Link both ways where it helps — a guide should point at the service, and the service should point back at the guide. Then run a crawl to list orphan pages and links passing through redirects, and fix those before writing anything new. Structured properly, internal links do much of the work people expect from on-page SEO without a word of new content.