Internal Linking Gap: Breadth vs Depth

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Intro

Two shops sell the same product. Their product pages are almost identical. Same specs, same photos, similar text. One ranks on page one. The other is stuck on page three.

The difference isn't on the page. It's in how you get to the page. On one site, it's two clicks from the homepage, with links from forty other pages. On the other, it's five clicks deep, behind pagination, with a single link pointing to it.

In this episode, we measure that difference: the structural gap.

Breadth, depth and inbound links

Three measurements describe internal structure.

Click depth. How many clicks from the homepage does it take to reach a page, following normal links? The homepage is depth zero. A page linked from the homepage is depth one, and so on.

Inbound internal links. How many different pages on your own site link to a page. Not counting the same link twice from one page.

And the shape: breadth versus depth. A broad site links to many pages from a few strong hub pages, so most pages sit two or three clicks down. A deep site has long chains. Category, subcategory, page two, page three, page four of a list, and then the product.

Why does it matter? Depth isn't a ranking factor you'll find in a list. It's a proxy. Pages that are close to the homepage and linked from many places are easier for crawlers to find and revisit, and they receive more of the site's internal link value. Deep, rarely linked pages tend to get crawled less and rank worse. That's the pattern I check for, not a magic number.

Crawl your own site

To measure this, you crawl. Start at the homepage, follow every internal link, and record each link as a pair: the page it's on, and the page it points to. A breadth-first crawl gives you click depth for free: the depth of each page is the level where the crawler first found it.

You can use a desktop crawler for this, or a small Python script, which is what I use, because the output goes straight into the same SQLite database as everything else. Same host only. Respect robots dot txt. One request at a time, with a short pause.

From the table of links, two queries give you everything. Depth per URL. And inbound links per URL, counted as distinct source pages.

Then one extra check. Compare the crawl with your sitemap. Any URL that's in the sitemap but that the crawler never reached is an orphan. It exists, you want it found, but no page links to it. Orphans are the most extreme depth problem there is.

Focus on the pages that matter

A full crawl produces a lot of numbers. Don't look at all of them. Look at the pages that matter.

That's two groups. First, the pages that already earn impressions in Search Console, especially the ones stuck on page two from episode ten. Second, the pages you're about to build or improve from the gap lists in episodes thirty-nine and forty.

For each important page, ask: how deep is it, and how many pages link to it? Here's what I see on our demo shop. Made-up numbers for illustration. The category pages are at depth one, with links from every page through the menu. Fine. But our twelve buying guides, and many best-selling product pages, sit at depth four or five, behind paginated lists, with only one or two inbound links each.

That's a structural problem. And no amount of rewriting the product text will fix it.

Compare with a competitor

Now the gap part. Run the same crawl on one core competitor. Politely, and with a cap, say two thousand pages. You don't need their whole site, you need its shape.

Compare two things. First, the depth distribution: what share of pages sit at each depth. In our example, competitor D has most pages at depth two or three. We have most at four or five.

Second, compare the same page type. Their product pages against ours. Theirs average around twenty inbound links. Ours, two.

Then look at how they do it. Usually it's one of a few things. Hub pages, like a buying guide that links to every product it mentions. Related-product blocks. Brand pages that list everything from one manufacturer. Breadcrumbs. Or simply category pages that show more products per page, so there's less pagination.

Often the fix for the structural gap is a page type from episode forty. A brand page isn't only something to rank. It's also a hub that pulls products up the tree.

The pitfalls

Three pitfalls.

Menus inflate the counts. If your main menu links to twenty categories, every page on the site links to them. That's real, but it hides the difference that matters: links inside the content. If your crawler can tell navigation from body content, store that as a separate column, and compare body links too.

Simple crawlers miss links added by JavaScript. If a related-products block loads after the page, a basic crawler won't see it. Google may or may not. Check a few important pages by hand, and see which links exist in the raw HTML.

And capped crawls cut the tree. If you stop the competitor crawl at two thousand pages, the deepest levels are missing. So compare like with like: shares at depth one to three, and the same page types, not totals.

The output: a structural gap list

What you get is a list of important pages, with your depth and inbound links next to the competitor's numbers for the same type of page, and a suggested fix. Usually the fixes are cheap compared with new content. A hub page, a related-links block, fewer pages of pagination.

And they're easy to re-measure. Crawl again after the change, and the depth either moved or it didn't.

One caution before you start moving links around. Don't flatten everything. If every page links to every other page, nothing stands out, and the menu becomes useless for people. The goal is that the pages that matter are close and well linked, not that the whole site sits at depth one.

Wrap-up

Same content, different structure, different results. The crawler and the depth report are linked in the description. Next episode: the authority gap, a light, cheap way to check whether backlinks are what's really holding you back. See you there.