The link building market has a problem nobody wants to admit. 80% of agencies selling link acquisition services use practices that, sooner or later, will cause you problems. Manual Google penalties. Unexplained traffic drops. Loss of authority built over years.
At SEOCOM we’ve been doing link building for 25 years and we’ve refused for 25 years to do it the way most of the industry does. It’s not ethical posturing. It’s accumulated experience: we’ve seen too many clients arrive with link profiles destroyed by previous agencies looking for fast results with dark methods.
This article is an exhaustive list of what we DON’T do and why. If another agency is offering you any of these practices, run. If you don’t know whether your current agency uses them, this checklist gives you the criteria to ask.
The 4 categories of dangerous practices
Category 1: Private Blog Networks (PBN)
A PBN is a network of domains that an agency (or an individual black-hat SEO) owns or controls, usually bought after expiring, used to generate artificial links to the sites that pay.
They’re sold as “links on sector-themed blogs” but in reality they’re zombie domains the agency fills with generic or spun content, often with authority inherited from the original domain before it expired.
Google detects them better every day because:
- Similar hosting patterns (same IPs, same registrars).
- Low-quality or duplicate content.
- Systematically link to the same client sites.
- Absence of real organic traffic (no one reads those blogs).
- Inbound link profiles that don’t match a real publisher.
The problem is that working with PBN is playing roulette. While Google doesn’t detect the network, it generates links. When it detects it (and it always detects it sooner or later), every site that received links from that network loses that authority at once. In the worst case, they receive a manual penalty for unnatural links.
We don’t do it. If your agency talks about “themed blogs we have” or “sector collaborator network” with dozens of domains never named, it’s a PBN in disguise.
Category 2: Individual link buying
There is a very active market for individual link sales. Portals charging between €30 and €300 for a contextual link in an article. The agency buys, the client receives the link, everyone apparently happy.
The problem is that these portals are mapped by Google. Most are:
- Low-quality generic news sites.
- Guest posting platforms without editorial criteria.
- Inactive blogs accepting paid articles.
- Pseudo-thematic directories.
Google has lists of suspicious domains constantly updated. One link from these sites doesn’t penalize, but the cumulative pattern does: if your link profile has 40 links from this type of site in 6 months, the footprint is obvious.
We don’t buy individual links. If an agency offers you a package of “10 links per month for X euros”, they’re buying. There’s no other explanation for that pricing and delivery model.
Category 3: Sponsored article farms
Platforms that describe themselves as digital media but only publish paid content. Their editorial criteria is nonexistent: any company can publish on any topic if they pay.
They’re distinguished from real media by several signals:
- Thousands of articles with different authors and no editor mentioned.
- Incoherent topics (one article about technology, next about makeup, next about nutrition).
- Absence of original news or reporting.
- Low organic traffic compared to content volume.
Google systematically devalues links from these sites. The authority signal they provide is close to zero and in extreme cases can be negative.
We don’t publish on article farms. If an agency shows you “publications in media” that are all from domains like this, the links are worthless.
Category 4: Comment spam, massive exchanges and automation
Practices that worked 15 years ago that some still do:
- Comments on dead blogs with links in the signature.
- Massive reciprocal exchanges (“you link me, I link you”).
- Software that generates automated links in forums, directories, open wikis.
- Registration in hundreds of directories without criteria.
100% of these practices have been detected by Google for years. They don’t provide authority, they dirty the link profile, they consume resources (and euros) that could be dedicated to building real authority.
We don’t even consider them. They’re not part of the debate about what “modern link building” is. They’re practices that should be extinct.
Why Google detects them better every day
10 years ago, Google’s algorithm for detecting artificial links was rudimentary. You could “fool” it with sophisticated patterns.
Today, the system combines:
- Massive analysis of hosting and registry patterns.
- Machine learning across millions of link profiles to identify anomalies.
- Comparison of the link profile with organic traffic and domain brand signals.
- Detection of temporal patterns (anomalous link spikes).
- Evaluation of the quality of the linking site (not just quantity).
What previously took 6 months for Google to detect is detected in weeks today. What went unnoticed before is flagged now.
What happens when someone penalizes you for link spam
Drop scenarios from toxic links are of two types:
Algorithmic penalty
The most frequent. Google automatically adjusts the value it gives to your links and your rankings drop without warning. No Search Console message. No explicit explanation. One day your positions are fine, the next day they’ve dropped 10-30 spots on key keywords.
Recovering from this is possible but takes 3-9 months: identify the problematic links, manage disavow, start building a clean profile, wait for Google to reevaluate.
Manual penalty
Less frequent but much more serious. A human Google reviewer evaluates your site and applies a manual penalty. You receive a Search Console notification with the reason (usually “unnatural links”). Your site can disappear completely from results until you fix the problem.
Recovering from this requires:
- Exhaustive link profile cleanup (identification + disavow of hundreds of links).
- Reconsideration request to Google with evidence of the cleanup.
- Waits of 4-12 weeks for reevaluation.
- Repeat if the first request is rejected (frequent).
We’ve seen projects take more than 12 months to recover from manual penalties for link spam inherited from previous agencies. It’s one of the most professionally frustrating scenarios.
What we do instead: real authority building
If these practices are prohibited, how do you build authority in 2026?
Digital press with real media
We work with real sector journalists and media. Getting a mention or link in a media outlet requires the content to be newsworthy: proprietary sector data, studies that contribute new information, expert opinion on trends. It’s real PR work, not paid publication buying.
Link earning through linkable content
Content designed to be cited: sector studies, useful free tools, exhaustive technical guides, original market data. When that content exists, other sector sites cite it naturally. It’s the most sustainable and expensive way but the one that generates real authority.
Strategic partnerships with sector organizations
Alliances with sector associations, institutions, events, professional communities. Links resulting from real collaborations are contextually relevant and transfer genuine authority.
Unlinked mention recovery
Many brands are mentioned in sector articles without an associated link. Identifying those mentions and contacting editorially to turn them into links is low-cost high-return work. But it requires methodology.
Competitive analysis and link gap
We analyze which sites link to our direct competitors but not to our client. If 20 sector media link to the competition but not to you, there’s real opportunity to close that gap with targeted editorial work.
The numbers don’t add up with the honest method
A frequent question: “Why do you charge €1,500/month minimum for link building when another agency offers me 10 links a month for €500?”
The answer is simple. Honest link building has high structural costs:
- Real journalists charge per publication.
- Linkable content production requires research and writing.
- Managing relationships with media and organizations is continuous work.
- One real quality link may require 10-20 hours of work between production, pitch, follow-up and validation.
When someone offers you 10 links a month for €500, the only economic models that fit are the ones described above: PBN, buying, farms. There’s no other way. The numbers are inappealable.
How to know if your current agency does clean link building
Checklist to evaluate your current provider:
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Ask for the last 20 links obtained. Are the sites real sector media with their own organic traffic and editorial criteria?
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Review the content where your link appears. Is it a real editorial article or clearly paid content without criteria?
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Ask about the acquisition model. Editorial relationships? Linkable content marketing? Or “we have a collaborator network”?
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Evaluate the price. If it’s very low, the methods will be dark. There’s no economic way to do honest link building at low price.
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Ask for case studies with link profiles before and after. Organic authority growth or suspicious spikes?
If you already have a problem
If after reading this you suspect your link profile may be damaged, it’s not something to fix alone. Cleanup of toxic profiles is specialized work: identifying problematic links with criteria (not every link from a “weird” site is toxic), careful disavow management (too aggressive can be counterproductive), starting to build a clean profile.
At SEOCOM we have specific experience recovering projects with link spam history. It’s one of the most common scenarios we receive. The good news: it’s recoverable in most cases. But the sooner you start, the better.
Contact us if your project has signs of problems from previous badly-done link building. We’ll honestly tell you if the case is recoverable and on what timelines.
