A link farm is a website, or a cluster of them, whose main purpose is to host large numbers of links to other sites. Pages are packed with links, often to unrelated businesses, and the content is thin or auto-generated. Link farms were common in the early 2000s, when raw link counts influenced rankings more directly, and they still exist as a source of spam links.
How link farms differ from PBNs
Both are link schemes. A link farm is usually obvious: pages of links with little attempt to look like a real publication. A private blog network tries to look like a set of independent, real blogs. In practice the line is blurry, and both are covered by Google's link spam policies.
Why sites end up with farm links
Some sites bought them years ago. Others pick them up without doing anything, because spam sites scrape and link to popular pages automatically. Low-cost "submission" services also place links on farms and spammy directories at volume.
Google has said its systems are generally good at ignoring this kind of junk link. Finding some in your backlink report is normal and is not by itself a reason to act.
When to act
Act if you, or an agency working for you, actively built the links; if you have a manual action for unnatural links; or if the volume is large and tied to a purchase. The usual steps are to request removal where possible and, if a manual action is in place or you have reason to expect one, disavow what you cannot remove.
Example
An inherited link profile
A new marketing lead at an illustrative IT asset tool, Gearmantle, reviews the backlink report and finds thousands of links from a handful of domains whose pages contain hundreds of unrelated links each. Invoices show a previous agency sold a "directory submission package". The team documents the links, requests removal and prepares a disavow file for the ones that remain.
Common mistakes
Buying bulk submission packages
Cheap packages that promise hundreds of links usually mean link farms and spam directories.
Disavowing every low-quality link you see
Random scraper links are common and usually ignored. Focus on links you or someone working for you created.
Questions
Google's systems are built to discount them, and the links carry policy risk. They are not a sound investment.
