What is a private blog network (PBN)?
A private blog network (PBN) is a set of websites owned or controlled by one person or company and used to link to another site so that site ranks higher. Wikipedia's summary describes a PBN as a "group of authoritative websites used as a source of contextual links that point to the owner's main website" [1]. For example, an affiliate marketer might control 30 small blogs on different domains, each publishing thin articles that link to the marketer's money site with keyword-rich anchors.
"Private" means the network is not open to the public and is hidden from search engines as far as the owner can manage. The sites are made to look independent, but they exist to pass links rather than to serve readers.
Search Insider does not support or suggest using private blog networks.
How does Google treat private blog networks?
Google treats private blog network links as link spam. 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" [2], which describes a PBN's purpose exactly.
Google enforces this in two ways. Automated systems, including SpamBrain and the link systems that absorbed Penguin, detect and devalue manipulative links [7][5]. Human reviewers issue manual actions: a site benefiting from a network can receive "Unnatural links to your site", which Google describes as "a pattern of unnatural, artificial, deceptive, or manipulative links pointing to your site" [4].
The policy text does not name PBNs. In October 2026, Search Insider checked Google's spam policies page and found no mention of "private blog network" or "PBN" [2]. PBNs fall under the general link spam rule and, where they are built on old domains, the separate expired domain abuse policy.
Are PBNs against Google's guidelines?
Yes. PBNs are against Google's spam policies because the network's links exist primarily to manipulate rankings, which is Google's definition of link spam [2]. Whether the links are bought from a network or placed on sites the owner controls makes no difference to that definition.
PBNs built on old domains can break a second policy. Google defines expired domain abuse as when "an expired domain name is purchased and repurposed primarily to manipulate search rankings by hosting content that provides little to no value to users" [2].
When did Google start penalizing PBNs?
Google took visible action against private blog networks in September 2014, when it issued manual action penalties to sites using them [3]. Wikipedia describes multiple deindexing campaigns against PBN users beginning that year [1].
2012: Penguin targets manipulative links
Google launched Penguin on April 24, 2012, against sites manipulating the number of links pointing to their pages [8]. Link networks of all kinds were among the practices it aimed at.
2014: manual actions against PBN users
In September 2014, Google issued manual action ranking penalties against sites using private blog networks, aiming to stop marketers using PBNs to boost rankings [3]. Several networks were deindexed in the same period [1].
2016: links devalued in real time
In September 2016, Penguin became part of Google's core algorithm and began devaluing spam links "rather than affecting ranking of the whole site" [5]. For PBN links, this means links Google identifies can stop counting without any notice to the site receiving them.
What is the difference between a PBN and a link farm?
A link farm is an open, often obvious group of sites that all link to each other, while a PBN is a hidden network built to look like unrelated, independent sites. Wikipedia defines link farms as "tightly-knit networks of websites that link to each other for the sole purpose of exploiting the search engine ranking algorithms" [1], and traces them to 1999 [3].
| Link farm | Private blog network | |
|---|---|---|
| Visibility | Often obvious, sites link to each other heavily | Disguised as independent sites |
| Typical sites | Low-quality pages built only for links | Blogs, often on expired domains with existing backlinks [1] |
| Link style | Reciprocal and bulk | Contextual links in articles [1] |
| Google's view | Link spam [2] | Link spam [2] |
Both are link schemes. The difference is in disguise, not in how Google classifies them.
What is the difference between a PBN and a guest post on a real blog?
A guest post on a real blog is published by an independent site with its own audience and editorial judgment, while a PBN post is published on a site that exists to sell or pass links. The test is the site, not the format: an article with a link looks the same in both cases.
The line matters for anyone buying links or placements. A link on an independent, trafficked site that is paid for still needs rel="sponsored" or rel="nofollow" under Google's policies [2]. A link on a PBN site is a problem even when nobody paid, because the site itself exists to manipulate rankings.
How do you spot PBN links?
To spot PBN links, look for sites that seem to exist only to link out. Common signs, useful in site vetting and backlink reviews:
- The domain has a past life. The site's topic or language changed abruptly, a sign of a repurposed expired domain [1][2].
- No real audience. Little or no search traffic, no comments, no social following, no named authors who exist elsewhere.
- Thin, generic articles on unrelated topics, each with one or two outbound commercial links.
- The same outbound targets repeated across several sites that appear unrelated.
- Hidden ownership. No about page, no contact details, or identical design and hosting across sites.
None of these signs proves a network on its own. Several together are a strong reason to avoid a placement or to review the link.
Do PBNs still work?
There is no published evidence that PBN links provide durable ranking gains, and there is clear evidence of risk. Google classes them as link spam [2], has penalized sites using them since 2014 [3], and devalues links its systems identify without telling the site [5]. Claims that a PBN "still works" come from people selling or using them and are not independently verified.
What is known is the downside: a manual action for unnatural links affects some or all of the site's visibility until every issue is fixed and a reconsideration request is accepted [4].
What should you do if your site has PBN links?
If your site has PBN links that you or a previous provider built, remove them where possible and disavow the rest. Google recommends disavowing when spammy links "have caused a manual action, or likely will cause a manual action" [6], and a known network is a likely cause. If a manual action already exists, fix every issue and file a reconsideration request [4].
If PBN links appeared without your involvement, Google says that in most cases it "can assess which links to trust without additional guidance" [6]. Monitor the Manual actions report rather than reacting to every unfamiliar link.