Buying an expired domain: what DA, DR, Trust Flow and referring domains tell you

The four numbers

Number	Whose	What it measures
Domain Authority (DA)	Moz	A 1–100 prediction of how likely the domain is to rank, compared with others. Moz says plainly it "is not a Google ranking factor".
Domain Rating (DR)	Ahrefs	The relative strength of the domain's backlink profile, 0–100, on a logarithmic scale. Going from 70 to 71 takes far more than going from 20 to 21.
Trust Flow (TF)	Majestic	0–100, built outward from trusted seed sites Majestic reviewed by hand. The closer a domain's links sit to those seeds, the higher it scores.
Referring domains	Any link index	How many different domains link to it. Not the same as backlinks: one site can link a thousand times.

Each company runs its own crawler and its own index, so the numbers disagree with one another. Treat them as three opinions, not as measurements.

How we combine them

Our own domain scanner ranks candidates with one sum:

score = DA + DR + 2 × TF + min(referring domains ÷ 50, 20)

Trust Flow counts double, because the others reward any link and Trust Flow rewards links near trusted sites. Referring domains are capped at 20 points, so a big count of weak links cannot carry a score. The scanner keeps a domain only if it is at least five years old, has at least 50 referring domains, and has DA 25+, DR 20+, or TF 15+ with 80+ referring domains.

A sum like this only sorts a list. It says which domains deserve a closer look.

What the numbers cannot tell you

What the domain used to be

Look it up in the Wayback Machine before you buy. This library's own domain, articleworld4u.com, was an article directory from 2007 to 2012. From 2019 it served Chinese-language pages about valves and industrial fittings. Any links the first life earned now point at a domain the second life filled with unrelated pages.

What the links say

We bought a domain with DA 23 and 193 referring domains. Every link we could open was hidden inside hacked sites, with gambling anchor text. The numbers counted them as strength. To see anchor text, open the linking pages. (How to find them.)

The shape of the link profile

That same domain had 113,247 backlinks from 193 domains: about 586 links from each linking site. Links repeated on every page of a site, in a footer or sidebar, produce a ratio like that. It is the mark of sitewide placement, paid or planted, not of 193 sites choosing to cite you.

How recent the links are

Moz reported that domain's DA up 2,200% in twelve months. A jump that size in a year means most of the links are new.

A checklist before you buy

1. Sort by a combined score. Shortlist the top.
2. Wayback: what was it, and was that life clean?
3. A live link index: who links now, and since when?
4. Open five linking pages: what does the anchor text say, and is the link visible?
5. Backlinks per referring domain: hundreds means sitewide placement.
6. Growth: a sudden rise means new links, probably placed ones.