Link spam
Google's spam policy category covering links intended to manipulate rankings: buying or selling links, excessive exchanges, automated link…
AlgorithmsWebspam update
Penguin
Google's link spam algorithm launched in 2012; since version 4.0 in 2016 it runs in real time within the core algorithm and devalues spam links rather than penalising sites.
In full
Early Penguin ran as periodic refreshes, so affected sites waited months for recovery even after cleanup — the situation that made the disavow tool essential. Penguin 4.0 changed the model to real-time, granular devaluation: bad links are discounted rather than causing a site-wide demotion. This is why Google now says most sites never need to disavow, and why link spam usually manifests as links simply not working.
Example
A site that bought anchor-heavy links sees them stop passing value entirely, with no manual action and no announcement.
Related terms
Disavow links tool
A Search Console tool for asking Google to ignore specified inbound links or domains, intended for sites with a link-related manual action…
SpamBrain
Google's AI-based spam prevention system, used to detect spam at crawl and ranking time and to identify and neutralise unnatural links.
Private blog network
A set of websites, often built on expired domains, controlled by one party for the purpose of passing links to money sites; a clear link…
Manual action
A demotion or removal applied by a human reviewer at Google for a spam policy violation, reported in Search Console with a reconsideration…
Where to read more
- Another Step to Reward High-Quality Sites (Penguin) · Landmark Post · developers.google.com