Link Schemes: What Google Penalises and Why
What Google counts as link spam, from paid links and link exchanges to link farms, plus a short history of Penguin and what happens if you're caught.
A link scheme is any attempt to create links to or from a site primarily to manipulate search rankings. Google now calls this link spam, and it's one of the practices named in its search spam policies.
The policy matters because links are still one of the signals Google uses to judge which pages deserve to rank. Anything that fakes that signal is what Google's spam systems are built to catch.
This guide sticks to what Google has actually documented, as of its spam policies page updated in August 2026.
What is a link scheme?
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." The key word is primarily. Links are allowed to help your rankings; they're not allowed to exist only for that reason.
Older SEO guides use the phrase "link schemes" because that was the name of Google's previous guidelines page. The idea is the same, the policy page has simply moved.
What Google lists as link spam
These are the examples on Google's spam policies page, with what they usually look like in the real world.
| Google's example | What it looks like in practice |
|---|---|
| Buying or selling links for ranking purposes | Paying for a followed link, or swapping goods or services for one |
| Excessive link exchanges or partner pages | "You link to me, I'll link to you" at scale |
| Automated programs or services that create links | Comment, forum and profile link blasts |
| Requiring a link in terms of service or contracts | Forcing a followed credit link with no option to qualify it |
| Text ads or text links that don't block ranking credit | Sitewide paid links without nofollow or sponsored |
| Advertorials that pass ranking credit, or optimised anchors in guest posts and press releases | Paid articles with keyword anchors, syndicated release links |
| Low-quality directory or bookmark links | Mass submissions to directories nobody visits |
| Links hidden in widgets distributed across sites | Free tools or badges carrying keyword links |
| Widely distributed footer or template links | "Designed by" or partner links across hundreds of sites |
| Forum comments with optimised links | Keyword links in posts and signatures |
| Low-value content created mainly to manipulate links | Thin pages published to host or attract links |
Hidden links get a separate section of their own, under hidden text and link abuse.
Paid links: when buying a link is allowed
Google's policy says plainly that buying and selling links is a normal part of advertising and sponsorship on the web. It isn't a violation as long as the link is qualified with rel="nofollow" or rel="sponsored".
So the problem isn't the payment, it's passing ranking credit through a paid link without saying so. A disclosed sponsored post is fine. A paid link dressed up as an editorial one is what the policy targets. The guide on dofollow vs nofollow links explains the rel attributes, and buying backlinks covers the practical risk of paying for followed links.
Link exchanges and reciprocal links
Reciprocal links happen naturally. Two companies that work together link to each other, or a supplier and a stockist reference one another, and nobody would call that spam.
Google's wording targets "excessive" link exchanges and partner pages built just for cross-linking. The warning signs are swaps with unrelated sites, swap requests sent at scale, and three-way arrangements (A links to B, B links to C, C links to A) designed to hide the trade.
Link farms and automated links
A link farm is a group of sites that exist mainly to link to each other or to sell links. Private blog networks are the more polished version, usually built on expired domains to borrow their old authority.
Google's policies cover these from several angles: buying and selling links, automated link creation, low-value content made to manipulate links, and a separate policy on expired domain abuse. They're the textbook definition of black hat, and the white hat vs black hat guide places them at the high-risk end of the spectrum.
What about link velocity?
Link velocity is an industry term for how fast a site gains links. Google's documentation doesn't mention it, and Google has never published a "safe" rate.
The rule of thumb in the industry is that pace should match reality. A viral digital PR story can earn hundreds of links in a week and that's perfectly natural. Hundreds of paid links appearing on a brand new site with no news to explain them is the kind of pattern people worry about, but the problem there is the links, not the speed.
Google Penguin: a short history
Penguin was Google's first big algorithm aimed specifically at link spam. Google's own ranking systems guide describes it as a system designed to combat link spam, announced in 2012 and integrated into the core ranking systems in 2016.
| Date | What changed | Why it matters now |
|---|---|---|
| April 2012 | Penguin launched to tackle link spam | Exact-match anchors and bought links stopped being a safe shortcut |
| September 2016 | Penguin became part of the core algorithm, running in real time | Google said it would devalue spam by adjusting ranking based on spam signals, rather than affecting the ranking of the whole site |
| September 2019 | rel="sponsored" and rel="ugc" introduced, nofollow treated as a hint |
Paid and user-generated links now have their own labels |
| July 2021 | Link spam update, with a reminder to qualify affiliate, sponsored and guest post links | Google asked for rel="sponsored" on affiliate and paid links and rel="nofollow" on guest post links |
| December 2022 | Link spam update using SpamBrain | Google said SpamBrain can detect sites buying links and sites used to pass outgoing links, and neutralise those links |
Penguin no longer runs as a separate update, so you won't see "Penguin refreshes" any more. Its job is done by the core ranking systems and spam detection systems such as SpamBrain.
What happens when Google spots a link scheme?
Google says it detects policy violations through automated systems and, where needed, human review that can lead to a manual action.
| Response | What triggers it | What to do |
|---|---|---|
| Links ignored | Automated systems discount the links | Nothing to fix, but stop paying for links that don't count |
| "Unnatural links to your site" manual action | A reviewer finds manipulative links pointing at you | Remove or nofollow what you can, disavow the rest, request reconsideration |
| "Unnatural links from your site" manual action | Your site appears to sell or trade links | Remove the links or qualify them with nofollow or sponsored |
For most sites the first row is the realistic outcome. The second and third are where a backlink audit and the disavow tool come in.
The short version
- A link scheme, now called link spam, is creating links primarily to manipulate rankings
- Google's spam policies list the patterns: paid links passing credit, excessive exchanges, automated links, widget and footer links, low-quality directories and optimised anchors in advertorials and press releases
- Paying for a link is allowed if it's marked
rel="sponsored"orrel="nofollow" - Penguin launched in 2012 and became part of the core algorithm in 2016, where it devalues spam instead of punishing whole sites
- Link velocity isn't a documented Google concept, the quality of the links matters far more than the pace