Settle in and get ready to take notes – this is important information for every digital marketer and online business. There may be a new negative SEO attack in town, and this time, it has the ability to seriously hamper SEO campaigns for even the most upstanding website owners. Known informally as “canonical negative SEO,” what makes the exploit so concerning is its near-impossibility to detect.
I expect that Google will eventually close this loophole. In the meantime, here’s what you need to know to keep yourself protected.
Canonical Basics From Google
Before we get into the how’s and why’s of canonical negative SEO attacks, it’s important to understand exactly what “canonical” means and how it applies to you. If you’re an SEO expert or marketer, you may already understand the basics; if so, feel free to skip ahead to the next section.
If you aren’t, or if you’re just getting started as a layperson, here’s what canonical is (and what it is does). “Canonical” is an HTML tag used by webmasters to tell search engines, like Google and Bing, that the content they’ve crawled is identical to other pages on or off the site. It essentially prevents web crawlers from double-indexing the same page multiple times, which can be interpreted as duplicate content even if the duplicate pages have a real purpose and use.
Webmasters must first choose the preferred page and then insert a link that looks like this into the header:
<link rel=”canonical” href=”http://example.com/blog/your-blog/”>
The link, of course, is the main page you want to indicate is “preferred” for crawlers.
Rel=canonical does not apply to visitors, so you don’t need to worry about your visitors needing to choose a preferred version. If you do choose to provide access to multiple versions (such as languages), there are other much clearer ways to provide access. This tag is specifically targeted to search engines.
When Should You Use Rel=Canonical?
There are a few very specific reasons webmasters would use rel=canonical, and moreover, would have duplicate pages on a website or network in the first place. The most common use here is on websites that allow pages to render under both www.example.com and http://example.com. The first gives a bit more DNS flexibility, while the second doesn’t carry advantage, but many webmasters allow both just in case visitors type in the wrong link.
Other instances when you might (or should) use rel=canonical include:
- When your content is syndicated over your network
- When you have pages in more than one language
- When multiple pages display the same content (e.g., product search)
- When you have a specific print-friendly or PDF downloadable page
- When two or more subdomains lead to the same content (e.g., webshops)
- Any other time two pages are identical, yet one should be the main focus
When you use rel=canonical, it essentially tells google the page you link to is the only page that matters. This influences rank by weakening the influence of non-canonical pages.
Which brings us to how people may be using this trend in negative SEO…
How Marketers Abuse Canonical Links
So, how exactly can unscrupulous marketers abuse canonical links? After all, if they could use them in such a way, wouldn’t Google have locked down this decades-old loophole long ago?
The theory here is that another webmaster can essentially just copy the entire header, including the rel=canonical tag itself, and paste it into a self-generated spam website page. Because rel=canonical combines rank scores for multiple pages, the search engine may count the spam page as a qualifier, dropping rank scores for the attacked page.
Even more frighteningly, there’s virtually no way to find pages using the same header or rel=canonical tag as yourself. So, if someone were to utilize this concept, you would most likely only find out once you see your scores dropping.
Wait – Are Canonical Attacks Real?
There are two schools of thought in this answer: yes, they’re real, and more people are using them than we think, and yes, they’re real, but it’s a weak tactic few webmasters would use. Either way, the potential for rel=canonical to be abused does exist, and that means you should protect yourself from it whenever you can.
As for Google, they spoke out about this specific issue – and unfortunately, they’re refusing to acknowledge it thus far. Most of their response seems to be that if it was going to happen, it would have happened already. But this hasn’t stopped webmasters from abusing other older strategies in the past, like XML.
The Problem With Cross-Site Negative SEO
Cross-site negative SEO does happen. While this specific strategy isn’t the most common, the potential for how it might be used is concerning enough that you should consider it if you can’t figure out why your rank is dropping. Unfortunately, it’s far from the only cross-site negative SEO attack out there.
The biggest problem in negative SEO attacks is malicious link-building at the hands of competitors. Black hat SEOs will take a website’s url and manually list it on known link building scheme networks, directories, and other websites on Google’s list of “known manipulation tactics.” That’s why Google created their disavow links tool.
Theoretically, if someone was abusing rel=canonical to attack you, and you identified the site, you could simply disavow it. What isn’t yet clear is how you should identify it or even if it’s enough of a problem to really even be concerned.
In terms of “negative SEO,” the much bigger concern for today’s businesses isn’t linkbuilding schemes or even rel=canonical; it’s hacking and/or reputation destruction. It takes only a single insecure, out-of-date WordPress plugin or weak FTP password to lead to a deleted site (or worse, adult content all over your PG pages). And a competitor can easily file fake reviews slamming you anywhere from YELP to Google Reviews.
The biggest takeaway from all this is what SEO needs to be wholistic, meaning you shouldn’t over-focus on any one aspect of your campaign. And you shouldn’t even really over-focus on negative attacks; instead, strive to engage in positive, honest strategies that foster real, organic relationships with your audience. Not only will you improve your growth, but that growth will endure over time, too, unlike other unscrupulous tactics.
