Link Equity and Domain Authority Are Not the Same Thing
Link equity is the ranking value that passes from one page to another through a hyperlink. It is a real signal inside Google's algorithm — rooted in PageRank — and it flows at the page level, through individual links, shaped by factors like the linking page's authority, the link's placement, anchor text, and whether the link carries a nofollow attribute.
Domain Authority (DA) is a third-party metric created by Moz. It scores a domain on a 1–100 logarithmic scale based on the quantity and quality of inbound links pointing to that domain. Google does not use DA in its ranking algorithm. It is a proxy metric, useful for benchmarking, but it is not a direct input into search rankings.
The core distinction: link equity is a mechanism inside Google's actual system, while Domain Authority is an external estimate of a site's overall link profile strength. Confusing the two leads to misallocated SEO effort.
How Each One Works Mechanically
Link equity flows through the web like a current. A page with many strong inbound links accumulates equity, then distributes a portion of it to each outbound link on the page. The more outbound links on a page, the smaller each share. A dofollow link from a page with high accumulated equity passes more value than a dofollow link from a page with almost none. Nofollow, sponsored, and ugc link attributes tell Google not to pass equity through that specific link.
Domain Authority is calculated by Moz's proprietary crawl. It aggregates the link signals pointing at an entire domain — number of unique linking root domains, the authority of those domains, spam signals — and compresses them into a single score. Because it is logarithmic, moving from DA 20 to DA 30 is easier than moving from DA 70 to DA 80. The score updates as Moz re-crawls the web, independent of any changes Google makes to its own algorithm.
A practical mechanical difference: link equity is page-specific and directional. A product page on a DA 60 site can receive very little link equity if the specific page linking to it has no inbound links of its own. DA gives no visibility into that page-level nuance.
Where They Overlap — and Where They Diverge
The overlap is real. A domain with a high DA score typically has strong pages that carry substantial link equity. Earning a link from a high-DA domain is a reasonable proxy for earning a link that passes meaningful equity — which is why DA became a popular shorthand in link-building outreach. In practice, a link from a DA 70 publication will usually pass more equity than a link from a DA 15 blog, all else equal.
The divergence appears in specific scenarios. A high-DA domain with a deeply buried, zero-traffic page linking to your store passes little equity regardless of the domain's overall score. A topically relevant niche site with a DA of 35 but a tightly linked community can pass more practical equity than a generic DA 60 directory. Domain Authority smooths over these page-level and topical-relevance factors entirely.
Another divergence: link equity is affected in real time by Google's crawl and index updates. Domain Authority is a periodic snapshot from Moz's crawler. The two can drift — a domain can lose ranking power quickly if Google re-evaluates its links, while its DA score lags behind.
When to Use Each Metric in Ecommerce SEO Decisions
Use Domain Authority as a fast filter during link prospecting. When evaluating hundreds of potential link partners or editorial sites, DA gives a quick signal to prioritize outreach. Sites below DA 20 warrant scrutiny; sites above DA 50 in a relevant vertical are generally worth pursuing. DA is also useful for competitive benchmarking — comparing your domain's score to direct competitors gives a rough sense of the link profile gap you need to close.
Use link equity thinking when making on-site decisions: internal linking architecture, crawl budget allocation, and category page structure. When an ecommerce site has hundreds of product pages, deciding where to concentrate internal links is a link equity distribution problem, not a DA problem. Pointing strong internal links to priority category pages, keeping link counts per page manageable, and avoiding orphaned pages are all link equity decisions.
For external link building, the most accurate evaluation combines both: DA as a quick filter, followed by a page-level check on the actual linking URL's inbound links and relevance. A link from a specific page on a DA 45 site that itself has strong inbound links can outperform a sitewide footer link on a DA 60 site.
Common Mistakes When Treating Them as Interchangeable
The most common mistake is treating DA growth as proof that link equity has increased. DA can rise because a site acquired links from other high-DA domains, but if those links are on pages Google rarely crawls or finds irrelevant, actual ranking improvement may not follow. Chasing DA as a goal in itself disconnects SEO effort from ranking outcomes.
A second mistake is over-relying on DA to evaluate competitor backlink profiles. A competitor with a lower DA than yours can still outrank specific product or category pages if they have concentrated link equity on those exact pages from topically authoritative sources. Page-level analysis with tools that show URL-level link data — not just domain-level DA — reveals the real competitive picture.
For ecommerce stores, misapplying these metrics often shows up in link-building briefs that only specify a minimum DA threshold. Without also specifying topical relevance, page-level authority, and dofollow status, the brief produces links that look good on a DA dashboard but move rankings minimally.
Actionable Priority: Which Signal to Optimize First
Start with link equity on-site before pursuing off-site DA improvement. Audit internal links to ensure that the highest-priority category and product pages receive the most internal link equity. Fix orphaned pages, reduce excessive outbound links on high-equity pages, and confirm that navigation links reinforce the pages that need ranking support. These changes operate inside the actual Google system and produce ranking impact without requiring external outreach.
Once internal link equity distribution is sound, use DA as a directional signal for external link acquisition — prioritizing relevant domains with DA above your own domain's score, then drilling into page-level metrics before committing outreach effort. Treat DA as a map and link equity mechanics as the territory. The map is useful; the territory is what Google actually measures.