How to Vet a Link Building Agency
A checklist for vetting a link building agency before you sign: what to ask about site selection, reporting, guarantees and where its links actually come from.
Vetting a link building agency means asking it to show real, live placements before you pay, explain exactly where its links come from, and separate its guarantee of "link goes live" from any claim about rankings, which no legitimate vendor controls. An agency that dodges any of those three is a real risk, not just an inconvenience.
This checklist assumes you already understand what legitimate link building looks like. The link building guide covers the full landscape first, so the red flags below make sense against a real baseline rather than in isolation.
On this page
What should you ask before the first call even ends?
Three questions separate a legitimate agency from a risky one fast. First: can you name three live sites you have placed on in the last two months, in a niche close to mine? Second: where does the link actually come from — outreach to a real editor, a marketplace, or something else? Third: what happens if a placed link disappears in six months?
Ask for three recent, live placements
Not a case-study page. Three URLs you can open right now, close enough to your industry that the relevance argument holds up.
Ask how the site was chosen
A real answer names actual criteria — topical relevance, real traffic, an editorial team that reviews submissions. A vague answer about 'high authority' with no further detail is a tell.
Ask what a replacement policy actually covers
Get the exact wording in your contract, not a verbal promise on the sales call.
Ask how many links they place on the exact same site each month
An agency reusing the same handful of sites for many clients is running something closer to a marketplace than bespoke outreach, whatever it calls itself.
What does a private blog network actually look like from the outside?
A cluster of sites, often dozens, built or bought purely to host outbound links, usually with thin or generic content and no real audience. They are harder to spot than they once were — better ones vary their design and hosting — but a few patterns still show up: content that reads as filler rather than something written for a real reader, a "yes" to almost any niche you propose, and site metrics that look strong while the actual traffic and engagement numbers do not back it up.
What are the common excuses, and what do they actually mean?
Most agencies that are cutting corners do not say so directly — they give an answer that sounds reasonable until you notice what it avoids. Learning the pattern of these excuses is faster than trying to memorise every possible red flag.
"We can't disclose our sites, it's proprietary" is the most common one, and it does not hold up: showing a client a live, already-published link tells a competitor nothing they could not find by searching your brand name themselves. "Rankings take time, trust the process" is a fair statement about SEO generally and a poor answer to a specific question about where a link came from — the two questions are not the same, and a vendor that conflates them is dodging. "Our authority score is X, that's all that matters" ignores that a metric from a third-party tool is an estimate, not a guarantee any human reader or crawler treats the site as trustworthy.
How do you check a proposed site is real, not just numbers on a dashboard?
Authority scores from third-party tools are a starting filter, not proof of anything. Open the site itself: does it have a real homepage, other articles that look genuinely written for readers, an About page, a working contact form, and — where you can check — some real social or search visibility beyond the one page your link would sit on [3]. Google's own guidance on evaluating outbound links points at the same basics: does the site look reputable, and would you trust it on its own merits, link aside [2].
| Green flag | Red flag |
|---|---|
| Real articles by different, named writers | Generic, unattributed 'admin' or 'staff' posts only |
| Content topically close to your industry | Willing to publish in almost any niche you name |
| Traffic and social signals match the authority score | Strong authority score, near-zero visible engagement |
| Clear editorial process, can reject a pitch | Will publish anything for the fee, no review |
| Contact details resolve to a real team | No verifiable owner, contact, or physical presence |
What should the contract actually say?
Get the replacement policy, the reporting cadence, and the definition of "placement" in writing. "Placement" should mean a live, indexed, followed link on the page you were shown — not a link buried in a sidebar widget that gets rotated out a month later. Ask what reporting looks like: a real agency sends you the actual URL of each link as it goes live, not a monthly PDF summarising a number with no way to verify it.
Price alone tells you surprisingly little here. A marketplace-style placement can be cheap and still legitimate if the site is real and the link is disclosed correctly; a bespoke, heavily researched placement on a strong industry site is fairly priced much higher. What matters is whether the price matches the process the agency describes — a bespoke-outreach story attached to a $50 flat rate is the mismatch worth questioning, not the price by itself. If cost is the whole reason you are close to signing, buying backlinks is worth reading first, because the cheapest option is sometimes the one most likely to trigger a manual action later.
Also get clarity on ownership of the relationship once the contract ends. Some agencies claim ongoing "maintenance" fees to keep a link live indefinitely, which is a reasonable model if disclosed upfront and a bad surprise if it appears only after the first invoice. Ask directly whether a link stays live with no further payment once placed, and get that answer in the same document as the price.
How do you judge reporting once the work has actually started?
The report itself is a vetting signal, not just a deliverable. A useful monthly report names the exact URL of every new link, the anchor text used, and the date it went live — information you could verify yourself in five minutes per link. A report that instead shows only aggregate counts, a rising authority-score chart, and no individual URLs is much harder to check, and that opacity is often the point.
Cross-check a sample of the reported links yourself, at least once. Open two or three of the URLs in the report, confirm the link is actually live, followed unless disclosed otherwise, and pointed at the right page. This takes fifteen minutes a month and catches the single most common failure mode in this business: links that were reported as delivered and quietly removed weeks later, well after the report was already filed and paid for.
The single question that tells me the most in a vendor call is the simplest one: show me a live link, right now, on your screen share. An agency that hesitates there is telling you something no case study will.
Is an in-house team ever a safer bet than any agency?
Sometimes, if you have the staff and the patience for it. In-house outreach removes the vendor-trust problem entirely, because you control every site your team pitches. What you give up is speed, an existing relationship list, and — in most small teams — the outreach volume a specialist vendor can sustain week over week. A broken-link approach is one of the lower-risk ways to start building in-house muscle before committing to any paid agency, because the whole tactic depends on genuinely useful outreach rather than a purchased placement — see broken link building for how it works.
What if you want press coverage instead of a placed link?
That is a different service entirely, even though the pitch process looks similar from the outside. A link building agency is optimising for the link; a digital PR agency is optimising for the story, and the link is something you ask for once it runs. Digital PR vs link building breaks down which one actually fits your situation before you vet either kind of vendor.
Questions people also ask
What is the single biggest red flag when vetting a link building agency?
Refusing to name a live site before you pay. An agency confident in its inventory will show you real, checkable placements; one that will not is usually hiding either low-quality sites or a network it does not want you to trace.
Are private blog networks always obvious to spot?
Not always from the outside, but a few tells help: thin, generic content across many domains, similar site design or hosting patterns, and a suspiciously easy 'yes' to every niche you ask about. Ask directly whether links come from a PBN and watch how the answer is phrased.
Should an agency guarantee a specific ranking result?
No legitimate agency can guarantee a ranking, because no vendor controls Google's algorithm. A guarantee should cover what the agency does control: the link goes live, stays live, and gets replaced if it drops — not where you rank for a keyword.
How many links a month should a good agency recommend?
It depends on the site's age and existing profile, and a good agency will ask about both before proposing a number rather than quoting a flat monthly volume to every client.
What is a fair price range to expect from a legitimate agency?
Wide enough that the number alone tells you little — a marketplace-style placement can run under $200 and a bespoke, researched placement on a strong site can run into four figures. The site quality and the process behind it matter more than the sticker price.
Sources
- Google Search Central spam policies — Google Search Central (checked 23 September 2026)
- Qualify outbound links to Google — Google Search Central (checked 23 September 2026)
- Link building: the complete guide — Ahrefs (checked 23 September 2026)
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Who wrote this
Ibrahem HelalCo-founder
Leads strategy and delivery.
Works on: SEO, GEO
Reviewed before publishing by Jeremy Zava, Co-founder.
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