Link farms: what they are, how to spot one and why a PBN isn't one

At a glance

• A link farm is a site or group of sites that exists to link out to other sites in bulk, usually for money or in exchange for links, with little real content or audience.
• Link farming started as rings of sites linking to each other and today mostly means sites that sell links to anyone who pays.
• Google’s spam policies list buying and selling links and excessive link exchanges as link spam, and Google says its systems work to nullify such links.
• You can spot a farm by its outbound links to unrelated niches, “write for us” offers, and high authority scores with little or no organic traffic.
• A private blog network you own and never sell links from is different on the two points that matter: who can get a link, and whether the sites look like real sites.

What a link farm is

How link farming works

The early version was simple: a group of sites agreed to link to each other, so every member gained dozens of links overnight. Pages full of reciprocal links, “partner” pages and link directories were common.

Search engines caught on, and the farms changed shape. Today they mostly come in four forms:

• Link-selling sites are blogs that publish a paid post or add a paid link for anyone, on any topic.
• Guest-post farms have a public “write for us” or “sponsored posts accepted” page and accept any article that comes with a fee.
• Auto-generated sites are pages created by software, often with spun or scraped text, that exist to hold links.
• Public blog networks are blogs on expired domains that sell links to all comers. These call themselves PBNs, but as our PBN guide puts it, “If anyone can buy a link, those are coming from public blog networks.”

What all four share is a business model: the site earns money from outbound links, so it accepts as many as it can.

Link farm vs link exchange vs public network vs private network

The term gets applied to anything with links in it. The differences come down to who owns the sites, who can get a link, and what the sites look like.

	Link farm	Link exchange	Public blog network	Private blog network you own
Who owns it	A seller	Two or more site owners	A seller	You
Who can get a link	Anyone who pays	Partners who link back	Anyone who pays	Only your own sites
Outbound link pattern	Many unrelated niches	Reciprocal, easy to see	Many unrelated buyers	A few of your sites, plus normal outbound links
Content	Thin, spun or off-topic	Varies	Often thin	Restored and new niche content
How Google’s policies describe it	Buying or selling links	Excessive link exchanges	Buying or selling links	Against Google’s guidelines, like all link building

The last row is worth reading closely. Our stance is that every link building tactic, outreach and guest posts included, runs against Google’s guidelines, so a private network isn’t special in that respect. Where it differs from a farm is in what can be detected. A farm sells to everyone, so its outbound links form a pattern nobody could mistake. A private network sells to no one, and if it is built well, its sites look like ordinary niche blogs. That is why the old claim that a PBN is “a special case of link farming” gets it backwards. If you want the full picture, see what a PBN is.

How Google treats link farms

Google’s spam policies define link spam as “the practice of creating links to or from a site primarily for the purpose of manipulating search rankings”, and list among the examples “Buying or selling links for ranking purposes” and “Excessive link exchanges (“Link to me and I’ll link to you”) or partner pages exclusively for the sake of cross-linking” (developers.google.com, fetched 2026-10-28). The same page says that “Sites that violate our policies may rank lower in results or not appear in results at all” and that review can “result in a manual action.”

In practice, Google mostly tries to ignore farm links rather than punish the sites they point to. Announcing its link spam update on July 26, 2021, Google said the update “is even more effective at identifying and nullifying link spam more broadly, across multiple languages” (Google Search Central Blog, fetched 2026-10-28). A nullified link doesn’t hurt you. It just stops counting, which means any money spent on it is wasted.

Manual actions for unnatural links do exist, and they show up in Search Console’s Manual actions report. If you get one, the fix is to remove what you can and disavow the rest, which our separate guide to the disavow tool covers.

How to spot a link farm

You can check most of these in a few minutes with Ahrefs or Semrush and the site itself:

• Every post links out to a different, unrelated niche: casinos next to dentists next to crypto.
• The site advertises “write for us”, “guest posts accepted” or “sponsored posts” to the public, often with a price list.
• Authority scores are high (Domain Rating, Domain Authority) but organic traffic is flat or close to zero.
• The same domain appears in the backlink profiles of many unrelated sites you look up.
• Posts are short, generic or spun, and written for the link rather than a reader.
• Anchor text on outbound links is exact-match commercial keywords, again and again.

Our PBN guide gives a simple test for any site: “think if it would be natural for a legitimate blog.” A real blog about gardening doesn’t link to a payday lender. The guide also names the outbound link pattern as one of the two most harmful footprints a network can leave, and a farm has that footprint by design. For the reverse question, see how to spot a PBN.

What to do if link farms link to you

Usually nothing. Most sites pick up links from spam sites they never asked for, and Google says its systems work to nullify link spam. Disavowing a handful of junk links is rarely worth the time.

Act when there is a reason to:

• You bought the links yourself, or a previous SEO did. Remove what you can.
• You have a manual action for unnatural links in Search Console.
• A sudden flood of spam links lines up with a ranking drop, which can be a sign of negative SEO.

For when links can do damage and how to judge them, see our guide to toxic backlinks. If you were pitched cheap links from a network, our breakdown of buying PBN links explains why we advise against it. For tactics that go well past farms, see black hat link building.

The alternative: links on sites you own

The problem with a farm is that its value depends on fooling search engines while selling to everyone. A private network you control avoids both problems. You decide which sites link where, nobody else buys from them, and the sites can be real niche blogs with restored and new content. Our guide’s rule is blunt: “Always build your own blog network, and don’t sell links on it.”

If you build one, Easy Blog Networks hosts each blog on a unique IP at a large hosting provider with that provider’s own nameservers, and keeps WordPress updated and backed up daily. Plans start at US$39/month for 10 blogs, with a 7-day free trial. The free PBN guide covers the rest.