SEO
6 Link Building Services That Actually Work (+6 More to Avoid)
Link building is hard work. Landing top-quality links takes a lot of time. Unless you have a dedicated in-house team of link builders, acquiring the links you need can be difficult, especially if you have more than one site you’re working on.
So if you’re a busy business owner or an SEO with multiple clients, how do you get the links you need while dedicating as little time as possible? By using a link building service.
But knowing the type of link building service you should be looking for can be overwhelming. That’s why we will walk you through the best link building services that work and those you should avoid.
We need to take a look at the link building service providers first, though.
OK, so here’s the thing:
Many link building service providers are beyond sketchy. The majority are selling the digital equivalent of a knock-off Louis Vuitton purse out of the trunk of their virtual car.
Every link building service website, marketplace page, etc., says “manual outreach” and “no PBNs.” But, for the most part, that isn’t the case.
That’s just a quick word of warning for you.
On the bright side, some fantastic link building agencies and freelancers work hard to win top-notch links that you’ll be happy to have on your site and will be proud to show off to your clients.
The tricky part is knowing what to look for to find these gems. Let’s look at some of the things you need to consider.
Reputation
This may seem obvious, but the reputation of an agency or freelancer needs to go beyond the testimonials on their website. Unless they’re reviews from well-known companies or industry professionals, I’ll usually assume these are fake.
Is the company one you’ve heard of before? Are the people behind the company well-known industry professionals?
Before reaching out to them, do some digging. Reading reviews beyond those on social media that anyone can buy is a good place to start.
Checking sites like Glassdoor to see what a company’s staff have to say about it can be a great way to evaluate its reputation. However, you should take these reviews with a grain of salt, as even the best company can have a disgruntled ex-employee.
Also, always be bold and ask other SEOs for their recommendations, either one to one or in groups and forums. Having someone advocate for a service they’ve used is one of the best ways to avoid disappointment.
Quality
Checking the quality of service the company provides is incredibly important, and I’m talking about more than the quality of the links it builds.
The customer service it provides, especially in the initial discovery and onboarding phases, can indicate what the service will look like in the long term.
You want to build a long-lasting relationship with a provider so that you don’t have to go through this process every few months. Knowing that the people you’re working with will take care of you and your sites makes all the difference.
You’ll want to work with a provider that can assess your site and curate a link building strategy designed to meet your individual goals. You’ll also want to work with someone who will get back to you reasonably quickly and is happy to jump on a call when needed.
Scalability
Something else to consider is whether a link building service provider can increase the number of links you want to acquire.
If you’re going to pay for link building services because you have many websites you can’t manage alone, you may run into the same issue with a freelancer or small agency.
Even if you plan to start small, if you’re thinking of scaling up in the long term, this is something you should discuss up front. It is better to find a high-quality provider you’re happy with that can grow with you rather than start again later.
So now we’ve covered what to look for in a service provider, let’s look at some good services that can actually move the needle.
After checking out some of the most popular link building agencies, I’ve found the top services that are most frequently offered across the board, including:
- HARO link building.
- Digital PR.
- Guest posting.
- Niche edits.
- Skyscraper link building.
- Managed link building.
It’s worth noting that most of these services are based on a particular technique or tactic used to acquire links rather than a link building service per se. But as this is how most agencies market them, it’s worth discussing them this way.
You can see an example from an established link building provider here:
And here:
Let’s look at not only what each service is but also the benefits of having a link building provider acquire those links for you and what you can expect to pay for each service.
1. Help a Reporter Out (HARO) editorial link building
Using HARO and alternatives to acquire editorial links from highly authoritative websites is the ultimate white hat link building technique.
Sites like Help a Reporter Out, Terkel, Dot Star Media, and the like allow journalists to post queries looking for sources for articles they are currently writing. If you’re an expert on that topic, you can give quality insights and be quoted (with a link to your site) in their article.
Not only can these links move the needle when coming from highly authoritative, niche-relevant sites that pass lots of link equity, but they can also help you improve experience, expertise, authority, and trust (E-E-A-T).
But are there benefits to using a service provider to build HARO links?
When it comes to well-established agencies that offer this service, they do a fantastic job of delivering the results you need with fully managed services. You only need to give them some initial information, and they will do the hard work for you.
However, they’re explicitly designed to scale these links and are working with multiple clients. To scale a fully managed service to that level, they usually have a large team of people pitching, tracking links, managing the accounts, liaising with clients, etc.
With that kind of team in place comes a higher cost. The average price range for this service with big agencies is $240–$700 per link.
Unless you’re working on a large brand, enterprise site, or portfolio of websites, it probably isn’t worth it. However, if you need more time or have too many sites to manage yourself, you can find a freelancer who can help you at a more budget-friendly price tag.
It’s worth mentioning that most good freelancers will still have the cost of paid tools to cover, and they’ll likely pitch for multiple clients on one platform. Not to mention the hard work and time that go into crafting quality pitches. You can find someone who can do the job well for $200–$350 per link.
2. Digital PR
Like HARO link building, digital PR is one of the best ways to build high-authority links while also gaining brand exposure, driving traffic, and improving E-E-A-T.
But unlike HARO link building—where you approach journalists who have already advertised their need for sources on a particular topic—digital PR techniques create creative campaigns that proactively approach journalists to get the word out about your business.
Many different techniques can be used, including:
- Press releases
- Data-led campaigns
- Newsjacking
- Reactive PR
Arguably, digital PR is something you can only do with the help of an agency. Unless you’re a PR expert yourself and have time to dedicate to it, you’re not going to get the same results as a quality agency can.
Digital PR is an “always-on” tactic that needs a team of people monitoring what’s trending that can put together an entire campaign as soon as something happens.
A great example is how search-first creative agency Rise at Seven quickly responded to this creative campaign from Marmite:
Within 45 minutes of this campaign going live, Rise at Seven executives responded with their creative version on behalf of their client, Auto Glass, which virtually responded to fix the broken windshield:
The high-quality work needed to execute digital PR tactics successfully comes at a high cost. Most digital PR agencies with an SEO focus have a minimum monthly retainer of between $4,000 and $15,000.
3. Guest posting link building
Building links through guest posting is the most popular way to build links among SEO professionals, according to Authority Hacker’s link building survey.
This service requires the provider to find high-quality, niche-relevant websites with a good amount of traffic and a strong backlink profile. Then the provider has to pitch the site admins topic ideas for a guest post to be added on the site.
This can be either offering to create an updated version of existing content that is currently underperforming or a new but relevant idea.
There’s a reason why guest posting is the most popular link building tactic among SEOs—because it works. Links are also relatively easy to achieve, as it is usually a win-win for both sites.
Plus, a quality service provider will have built up a database of sites it’s worked with and nurtured relationships with web admins, which means it can often acquire links easier than you would through hours and hours of outreach.
The thing is, quality comes at a cost. An agency offering guest posts as a service has a team of outreach specialists, content writers, and editors to produce the posts, plus site administration fees (the cost of someone to edit and upload the content) to cover.
If you want to build guest post links properly at scale, the average cost of $250–$400 per link is generally worth it.
4. Niche edits
Niche edits, also known as link placements, are where a link is placed on a site within an existing piece of content.
This can be that a current link in the content needs to be updated or fixed. Or simply because you think their audience will benefit from your content as a source of further reading.
Niche edit links can achieve similar results to guest post links but at a more budget-friendly cost (as there is no content to write). For this service, most reputable providers charge between $150 and $300 per link.
Be warned that many link building providers will simply buy these links. For the most part, providers will work from a list of sites that have link placement prices within a set budget.
For example, I have worked with agencies in the past that are willing to pay a fee of up to $100 for any link and they continuously do outreach to build upon that list. Then, whenever they need a link, they simply reach out to a relevant site and arrange for a link to be placed.
Obviously, buying links is something you need to be careful of, as it is against Google’s guidelines (unless the link contains a “nofollow” or “sponsored” link attribute). Many providers simply won’t inform you this is how they do business.
However, some will inform you that a site has asked for an additional fee and whether you are happy to pay that to give you the option. This is usually only the case for highly authoritative sites asking for $200+. But at least then, you can decide if this is something you’re happy to do.
5. Skyscraper link building
Skyscraper link building is a technique where you find a popular piece of content with lots of backlinks, and then you create your own (better) high-quality content to attempt to steal your competitor’s links.
When done well, skyscraper link building can land you dozens of high-quality links quickly. The problem is this tactic is a lot for one person to handle. You must do all the research, create content, find sites to reach out to, and then perform email outreach to gain links.
That’s why skyscraper link building is one of the best services you can outsource to an agency. Not only will it have a dedicated team to handle the entire process, but it will also have the professional tools needed to execute the services successfully at scale.
You can’t be surprised that this doesn’t come cheap. Most SEO agencies that offer skyscraper link building have different packages, depending on how many links you’re looking to build. They usually range from around $900–$3,000.
6. Managed link services
Managed link services and link packs are packaged services that agencies offer to cover all of your link building needs in one place. The idea is you will get a certain number of different types of links per month. For example:
- Five guest post links
- Three niche edit links
- Two HARO links
Some agencies will offer different packs at set prices for you to choose from. Others will charge a set retainer and customize link building packages based on your current backlink profile, competitor analysis, and goals.
If you’re someone with a large portfolio of sites or even a large enterprise site that doesn’t want the hassle of managing and training a dedicated in-house link building team, using a managed link building service from a reputable provider is worth it.
Prices can range between $2,500 and $10,000 per month.
Similar to how there are plenty of bad link building providers, link building services can be questionable at best and downright “black hat” at worst.
Even some well-known providers offer several services that aren’t for everyone, so it’s a good idea to know what you should avoid—even more so than what you’re looking for.
1. Anything cheap
Although paying someone $250 per hour to build links to your site doesn’t guarantee you’ll receive quality service, for the most part, you get what you pay for.
Most agencies will have a team that will spend hours performing outreach and producing content. Not to mention paid tools that allow team members to do their jobs well. So it’s reasonable to expect a particular price tag with a professional service.
Therefore, anyone on platforms like Fiverr, Upwork, or Freelancer offering 500 links for $10 will provide a service that either does nothing at all or, worse, more harm than good.
2. DA/DR increasing services
These services can be seen across freelancing platforms and guarantee to boost your Ahrefs’ Domain Rating (DR) or Moz’s Domain Authority (DA) above a particular metric. The idea is to make your site appear more authoritative than it is.
They involve spamming your site with a load of links that can look like this:
It’s worth stressing that both DA and DR are not considered by Google and hold no influence over your rankings. If your DR or DA is manipulated, it is solely to impress others using Ahrefs to check out your site.
These attempts of metrics manipulation naturally call for response from the SEO tool providers. Ahrefs worked on implementing changes to the DR calculation to try to make these artificial DR boosts ineffective.
3. Negative SEO links
Negative SEO links, or “SEO attacks,” as they are sometimes referred to, are spamming your competitors with poor-quality links in hopes of negatively impacting their rankings and traffic.
Usually, these services spam a site with millions of links at a minimal cost.
Not only is this completely unethical, it is also, quite frankly, downright lazy. And it most likely won’t do anything. If you’re spamming your competitor just to get a leg up on the competition rather than spending time building up your backlink profile, you’re doing SEO wrong.
4. Private blog networks (PBNs)
PBNs are a group of websites created specifically to link to one another and create the appearance that a website has “earned” backlinks from other websites.
By linking to your site from every other site in your PBN, you artificially establish trust signals in the hopes that Google will recognize them as legitimate websites and rank you higher.
Private blog networks used for link building are considered link spam and can land you with a Google penalty.
5. Press releases that aren’t newsworthy
A press release can be a genuinely helpful tool for building high-quality links and brand awareness when your company has something newsworthy to share, such as a merger or acquisition.
The issue arises when companies run a press release weekly solely to build links on everything from Karen-from-accounts’ new Labradoodle to “Flip-Flop Fridays.”
This is not only considered a spammy practice but will also most likely not be picked up by the sites you want to obtain links from. This makes them worthless.
6. Tiered links
Tiered link building is the practice of building links to pages you have already built links to your site from.
The idea is to increase the link equity to your site by improving the backlink profile of the page linking to yours.
This can work well when done correctly (by manually building high-quality links on each tier). I would never recommend doing this on a client site. But if you want to on your personal sites, that’s your choice.
Most tiered link building services involve spamming the Tier 1 site with low-quality links using automated tools like Money Robot. This unethical practice is used by SEOs who are happy to spam somebody else’s site with poor-quality links.
Final thoughts
Link building services can be the secret to SEO success for anyone who wants to build high-quality links at scale.
The key is finding a high-quality service provider that not only delivers what you need but also is someone you can work with in the long term and grow with you.
Have you got questions? Ping me on Twitter.
SEO
How to Revive an Old Blog Article for SEO
Quick question: What do you typically do with your old blog posts? Most likely, the answer is: Not much.
If that’s the case, you’re not alone. Many of us in SEO and content marketing tend to focus on continuously creating new content, rather than leveraging our existing blog posts.
However, here’s the reality—Google is becoming increasingly sophisticated in evaluating content quality, and we need to adapt accordingly. Just as it’s easier to encourage existing customers to make repeat purchases, updating old content on your website is a more efficient and sustainable strategy in the long run.
Ways to Optimize Older Content
Some of your old content might not be optimized for SEO very well, rank for irrelevant keywords, or drive no traffic at all. If the quality is still decent, however, you should be able to optimize it properly with little effort.
Refresh Content
If your blog post contains a specific year or mentions current events, it may become outdated over time. If the rest of the content is still relevant (like if it’s targeting an evergreen topic), simply updating the date might be all you need to do.
Rewrite Old Blog Posts
When the content quality is low (you might have greatly improved your writing skills since you’ve written the post) but the potential is still there, there’s not much you can do apart from rewriting an old blog post completely.
This is not a waste—you’re saving time on brainstorming since the basic structure is already in place. Now, focus on improving the quality.
Delete Old Blog Posts
You might find a blog post that just seems unusable. Should you delete your old content? It depends. If it’s completely outdated, of low quality, and irrelevant to any valuable keywords for your website, it’s better to remove it.
Once you decide to delete the post, don’t forget to set up a 301 redirect to a related post or page, or to your homepage.
Promote Old Blog Posts
Sometimes all your content needs is a bit of promotion to start ranking and getting traffic again. Share it on your social media, link to it from a new post – do something to get it discoverable again to your audience. This can give it the boost it needs to attract organic links too.
Which Blog Posts Should You Update?
Deciding when to update or rewrite blog posts is a decision that relies on one important thing: a content audit.
Use your Google Analytics to find out which blog posts used to drive tons of traffic, but no longer have the same reach. You can also use Google Search Console to find out which of your blog posts have lost visibility in comparison to previous months. I have a guide on website analysis using Google Analytics and Google Search Console you can follow.
If you use keyword tracking tools like SE Ranking, you can also use the data it provides to come up with a list of blog posts that have dropped in the rankings.
Make data-driven decisions to identify which blog posts would benefit from these updates – i.e., which ones still have the chance to recover their keyword rankings and organic traffic.
With Google’s helpful content update, which emphasizes better user experiences, it’s crucial to ensure your content remains relevant, valuable, and up-to-date.
How To Update Old Blog Posts for SEO
Updating articles can be an involved process. Here are some tips and tactics to help you get it right.
Author’s Note: I have a Comprehensive On-Page SEO Checklist you might also be interested in following while you’re doing your content audit.
Conduct New Keyword Research
Updating your post without any guide won’t get you far. Always do your keyword research to understand how users are searching for your given topic.
Proper research can also show you relevant questions and sections that can be added to the blog post you’re updating or rewriting. Make sure to take a look at the People Also Ask (PAA) section that shows up when you search for your target keyword. Check out other websites like Answer The Public, Reddit, and Quora to see what users are looking for too.
Look for New Ranking Opportunities
When trying to revive an old blog post for SEO, keep an eye out for new SEO opportunities (e.g., AI Overview, featured snippets, and related search terms) that didn’t exist when you first wrote your blog post. Some of these features can be targeted by the new content you will add to your post, if you write with the aim to be eligible for it.
Rewrite Headlines and Meta Tags
If you want to attract new readers, consider updating your headlines and meta tags.
Your headlines and meta tags should fulfill these three things:
- Reflect the rewritten and new content you’ve added to the blog post.
- Be optimized for the new keywords it’s targeting (if any).
- Appeal to your target audience – who may have changed tastes from when the blog post was originally made.
Remember that your meta tags in particular act like a brief advertisement for your blog post, since this is what the user first sees when your blog post is shown in the search results page.
Take a look at your blog post’s click-through rate on Google Search Console – if it falls below 2%, it’s definitely time for new meta tags.
Replace Outdated Information and Statistics
Updating blog content with current studies and statistics enhances the relevance and credibility of your post. By providing up-to-date information, you help your audience make better, well-informed decisions, while also showing that your content is trustworthy.
Tighten or Expand Ideas
Your old content might be too short to provide real value to users – or you might have rambled on and on in your post. It’s important to evaluate whether you need to make your content more concise, or if you need to elaborate more.
Keep the following tips in mind as you refine your blog post’s ideas:
- Evaluate Helpfulness: Measure how well your content addresses your readers’ pain points. Aim to follow the E-E-A-T model (Experience, Expertise, Authoritativeness, Trustworthiness).
- Identify Missing Context: Consider whether your content needs more detail or clarification. View it from your audience’s perspective and ask if the information is complete, or if more information is needed.
- Interview Experts: Speak with industry experts or thought leaders to get fresh insights. This will help support your writing, and provide unique points that enhance the value of your content.
- Use Better Examples: Examples help simplify complex concepts. Add new examples or improve existing ones to strengthen your points.
- Add New Sections if Needed: If your content lacks depth or misses a key point, add new sections to cover these areas more thoroughly.
- Remove Fluff: Every sentence should contribute to the overall narrative. Eliminate unnecessary content to make your post more concise.
- Revise Listicles: Update listicle items based on SEO recommendations and content quality. Add or remove headings to stay competitive with higher-ranking posts.
Improve Visuals and Other Media
No doubt that there are tons of old graphics and photos in your blog posts that can be improved with the tools we have today. Make sure all of the visuals used in your content are appealing and high quality.
Update Internal and External Links
Are your internal and external links up to date? They need to be for your SEO and user experience. Outdated links can lead to broken pages or irrelevant content, frustrating readers and hurting your site’s performance.
You need to check for any broken links on your old blog posts, and update them ASAP. Updating your old blog posts can also lead to new opportunities to link internally to other blog posts and pages, which may not have been available when the post was originally published.
Optimize for Conversions
When updating content, the ultimate goal is often to increase conversions. However, your conversion goals may have changed over the years.
So here’s what you need to check in your updated blog post. First, does the call-to-action (CTA) still link to the products or services you want to promote? If not, update it to direct readers to the current solution or offer.
Second, consider where you can use different conversion strategies. Don’t just add a CTA at the end of the post.
Last, make sure that the blog post leverages product-led content. It’s going to help you mention your products and services in a way that feels natural, without being too pushy. Being subtle can be a high ROI tactic for updated posts.
Key Takeaway
Reviving old blog articles for SEO is a powerful strategy that can breathe new life into your content and boost your website’s visibility. Instead of solely focusing on creating new posts, taking the time to refresh existing content can yield impressive results, both in terms of traffic and conversions.
By implementing these strategies, you can transform old blog posts into valuable resources that attract new readers and retain existing ones. So, roll up your sleeves, dive into your archives, and start updating your content today—your audience and search rankings will thank you!
SEO
How Compression Can Be Used To Detect Low Quality Pages
The concept of Compressibility as a quality signal is not widely known, but SEOs should be aware of it. Search engines can use web page compressibility to identify duplicate pages, doorway pages with similar content, and pages with repetitive keywords, making it useful knowledge for SEO.
Although the following research paper demonstrates a successful use of on-page features for detecting spam, the deliberate lack of transparency by search engines makes it difficult to say with certainty if search engines are applying this or similar techniques.
What Is Compressibility?
In computing, compressibility refers to how much a file (data) can be reduced in size while retaining essential information, typically to maximize storage space or to allow more data to be transmitted over the Internet.
TL/DR Of Compression
Compression replaces repeated words and phrases with shorter references, reducing the file size by significant margins. Search engines typically compress indexed web pages to maximize storage space, reduce bandwidth, and improve retrieval speed, among other reasons.
This is a simplified explanation of how compression works:
- Identify Patterns:
A compression algorithm scans the text to find repeated words, patterns and phrases - Shorter Codes Take Up Less Space:
The codes and symbols use less storage space then the original words and phrases, which results in a smaller file size. - Shorter References Use Less Bits:
The “code” that essentially symbolizes the replaced words and phrases uses less data than the originals.
A bonus effect of using compression is that it can also be used to identify duplicate pages, doorway pages with similar content, and pages with repetitive keywords.
Research Paper About Detecting Spam
This research paper is significant because it was authored by distinguished computer scientists known for breakthroughs in AI, distributed computing, information retrieval, and other fields.
Marc Najork
One of the co-authors of the research paper is Marc Najork, a prominent research scientist who currently holds the title of Distinguished Research Scientist at Google DeepMind. He’s a co-author of the papers for TW-BERT, has contributed research for increasing the accuracy of using implicit user feedback like clicks, and worked on creating improved AI-based information retrieval (DSI++: Updating Transformer Memory with New Documents), among many other major breakthroughs in information retrieval.
Dennis Fetterly
Another of the co-authors is Dennis Fetterly, currently a software engineer at Google. He is listed as a co-inventor in a patent for a ranking algorithm that uses links, and is known for his research in distributed computing and information retrieval.
Those are just two of the distinguished researchers listed as co-authors of the 2006 Microsoft research paper about identifying spam through on-page content features. Among the several on-page content features the research paper analyzes is compressibility, which they discovered can be used as a classifier for indicating that a web page is spammy.
Detecting Spam Web Pages Through Content Analysis
Although the research paper was authored in 2006, its findings remain relevant to today.
Then, as now, people attempted to rank hundreds or thousands of location-based web pages that were essentially duplicate content aside from city, region, or state names. Then, as now, SEOs often created web pages for search engines by excessively repeating keywords within titles, meta descriptions, headings, internal anchor text, and within the content to improve rankings.
Section 4.6 of the research paper explains:
“Some search engines give higher weight to pages containing the query keywords several times. For example, for a given query term, a page that contains it ten times may be higher ranked than a page that contains it only once. To take advantage of such engines, some spam pages replicate their content several times in an attempt to rank higher.”
The research paper explains that search engines compress web pages and use the compressed version to reference the original web page. They note that excessive amounts of redundant words results in a higher level of compressibility. So they set about testing if there’s a correlation between a high level of compressibility and spam.
They write:
“Our approach in this section to locating redundant content within a page is to compress the page; to save space and disk time, search engines often compress web pages after indexing them, but before adding them to a page cache.
…We measure the redundancy of web pages by the compression ratio, the size of the uncompressed page divided by the size of the compressed page. We used GZIP …to compress pages, a fast and effective compression algorithm.”
High Compressibility Correlates To Spam
The results of the research showed that web pages with at least a compression ratio of 4.0 tended to be low quality web pages, spam. However, the highest rates of compressibility became less consistent because there were fewer data points, making it harder to interpret.
Figure 9: Prevalence of spam relative to compressibility of page.
The researchers concluded:
“70% of all sampled pages with a compression ratio of at least 4.0 were judged to be spam.”
But they also discovered that using the compression ratio by itself still resulted in false positives, where non-spam pages were incorrectly identified as spam:
“The compression ratio heuristic described in Section 4.6 fared best, correctly identifying 660 (27.9%) of the spam pages in our collection, while misidentifying 2, 068 (12.0%) of all judged pages.
Using all of the aforementioned features, the classification accuracy after the ten-fold cross validation process is encouraging:
95.4% of our judged pages were classified correctly, while 4.6% were classified incorrectly.
More specifically, for the spam class 1, 940 out of the 2, 364 pages, were classified correctly. For the non-spam class, 14, 440 out of the 14,804 pages were classified correctly. Consequently, 788 pages were classified incorrectly.”
The next section describes an interesting discovery about how to increase the accuracy of using on-page signals for identifying spam.
Insight Into Quality Rankings
The research paper examined multiple on-page signals, including compressibility. They discovered that each individual signal (classifier) was able to find some spam but that relying on any one signal on its own resulted in flagging non-spam pages for spam, which are commonly referred to as false positive.
The researchers made an important discovery that everyone interested in SEO should know, which is that using multiple classifiers increased the accuracy of detecting spam and decreased the likelihood of false positives. Just as important, the compressibility signal only identifies one kind of spam but not the full range of spam.
The takeaway is that compressibility is a good way to identify one kind of spam but there are other kinds of spam that aren’t caught with this one signal. Other kinds of spam were not caught with the compressibility signal.
This is the part that every SEO and publisher should be aware of:
“In the previous section, we presented a number of heuristics for assaying spam web pages. That is, we measured several characteristics of web pages, and found ranges of those characteristics which correlated with a page being spam. Nevertheless, when used individually, no technique uncovers most of the spam in our data set without flagging many non-spam pages as spam.
For example, considering the compression ratio heuristic described in Section 4.6, one of our most promising methods, the average probability of spam for ratios of 4.2 and higher is 72%. But only about 1.5% of all pages fall in this range. This number is far below the 13.8% of spam pages that we identified in our data set.”
So, even though compressibility was one of the better signals for identifying spam, it still was unable to uncover the full range of spam within the dataset the researchers used to test the signals.
Combining Multiple Signals
The above results indicated that individual signals of low quality are less accurate. So they tested using multiple signals. What they discovered was that combining multiple on-page signals for detecting spam resulted in a better accuracy rate with less pages misclassified as spam.
The researchers explained that they tested the use of multiple signals:
“One way of combining our heuristic methods is to view the spam detection problem as a classification problem. In this case, we want to create a classification model (or classifier) which, given a web page, will use the page’s features jointly in order to (correctly, we hope) classify it in one of two classes: spam and non-spam.”
These are their conclusions about using multiple signals:
“We have studied various aspects of content-based spam on the web using a real-world data set from the MSNSearch crawler. We have presented a number of heuristic methods for detecting content based spam. Some of our spam detection methods are more effective than others, however when used in isolation our methods may not identify all of the spam pages. For this reason, we combined our spam-detection methods to create a highly accurate C4.5 classifier. Our classifier can correctly identify 86.2% of all spam pages, while flagging very few legitimate pages as spam.”
Key Insight:
Misidentifying “very few legitimate pages as spam” was a significant breakthrough. The important insight that everyone involved with SEO should take away from this is that one signal by itself can result in false positives. Using multiple signals increases the accuracy.
What this means is that SEO tests of isolated ranking or quality signals will not yield reliable results that can be trusted for making strategy or business decisions.
Takeaways
We don’t know for certain if compressibility is used at the search engines but it’s an easy to use signal that combined with others could be used to catch simple kinds of spam like thousands of city name doorway pages with similar content. Yet even if the search engines don’t use this signal, it does show how easy it is to catch that kind of search engine manipulation and that it’s something search engines are well able to handle today.
Here are the key points of this article to keep in mind:
- Doorway pages with duplicate content is easy to catch because they compress at a higher ratio than normal web pages.
- Groups of web pages with a compression ratio above 4.0 were predominantly spam.
- Negative quality signals used by themselves to catch spam can lead to false positives.
- In this particular test, they discovered that on-page negative quality signals only catch specific types of spam.
- When used alone, the compressibility signal only catches redundancy-type spam, fails to detect other forms of spam, and leads to false positives.
- Combing quality signals improves spam detection accuracy and reduces false positives.
- Search engines today have a higher accuracy of spam detection with the use of AI like Spam Brain.
Read the research paper, which is linked from the Google Scholar page of Marc Najork:
Detecting spam web pages through content analysis
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SEO
New Google Trends SEO Documentation
Google Search Central published new documentation on Google Trends, explaining how to use it for search marketing. This guide serves as an easy to understand introduction for newcomers and a helpful refresher for experienced search marketers and publishers.
The new guide has six sections:
- About Google Trends
- Tutorial on monitoring trends
- How to do keyword research with the tool
- How to prioritize content with Trends data
- How to use Google Trends for competitor research
- How to use Google Trends for analyzing brand awareness and sentiment
The section about monitoring trends advises there are two kinds of rising trends, general and specific trends, which can be useful for developing content to publish on a site.
Using the Explore tool, you can leave the search box empty and view the current rising trends worldwide or use a drop down menu to focus on trends in a specific country. Users can further filter rising trends by time periods, categories and the type of search. The results show rising trends by topic and by keywords.
To search for specific trends users just need to enter the specific queries and then filter them by country, time, categories and type of search.
The section called Content Calendar describes how to use Google Trends to understand which content topics to prioritize.
Google explains:
“Google Trends can be helpful not only to get ideas on what to write, but also to prioritize when to publish it. To help you better prioritize which topics to focus on, try to find seasonal trends in the data. With that information, you can plan ahead to have high quality content available on your site a little before people are searching for it, so that when they do, your content is ready for them.”
Read the new Google Trends documentation:
Get started with Google Trends
Featured Image by Shutterstock/Luis Molinero