Links

Unique referring domains

URDs · linking root domains

Definition

Unique referring domains is the same math as referring domains: hostnames with at least one link, counted once. Some dashboards say “unique” to remind you not to count 40 URLs on one paper as 40 domains. If your team already uses referring domain that way, you do not need a second metric. If someone is still reporting raw backlinks as the win, this name is the correction.

Say whether subdomains collapse.

How it works

Deduplicate on registered domain unless you have a reason to treat news.example.com as separate. Filter owned properties and wires. Report new vs repeat in the period.

Worked example

40 hrefs, 17 hostnames, 2 owned, 1 wire = 14 unique earned referring domains. A vendor screenshot of “40 backlinks” describes the same week.

How it differs

Referring domain is the term this glossary prefers. Backlink is the href. This alias exists because dashboards disagree.

Common errors

Counting http and https as two domains. Counting every subdomain of a publisher group as unique without saying so.

Sources