Jeff Baker

Hop into my time machine. We’re going back to 2013.

Google became smart and content marketing simply stopped working.

And when I say “smart”, I mean Google started figuring out the difference between crap content and quality content, among other things.

An entire industry of content mills chopped off at the knees. So the millions upon millions of 200-word news articles written specifically for robots became instantly worthless. Worse, they became toxic!

We were told by our Google overlords that “quality content” was going to be the key to success moving forward. And much like stock investors, we all speculated emotionally and irrationally on what “quality” could possibly mean.

We had so many ideas … Could it mean better grammar? Longer word counts? More evergreen content?

Or, could it mean writing more thoroughly on a particular topic so that you’ve satisfied the searcher intent better than your competitors?

Turns out it was the latter.

Enter TF-IDF tools, including Clearscope.

What is Clearscope?

Clearscope is a tool that supposedly helps writers create thorough content that ranks better than the competition’s. The tool works like this:

  1. You plug in a keyword.
  2. It scrapes the content of the top-20 results in Google for that keyword.
  3. It lists and prioritizes all the topics you could possibly discuss on the subject.
  4. You enter your content and it tells you the topics you properly covered, and those that you missed.
  5. It grades your content from A-F.

It’s basically a data-led blueprint for creating content that’s more comprehensive than your competitors’.

While the algorithm that makes all this functionality come to life is certainly complex, it’s actually based on a simple concept: TF-IDF.

“Term Frequency-Inverse Document Frequency” is a relatively straightforward mathematical technique for determining how important a word is in any given document. This isn’t even a new idea; As a matter of fact, the concept was introduced several decades ago.

Clearscope, and many newly emerging tools in the market, have managed to repurpose this technique for the web, and writing content for SEO in particular.

And the results of using TF-IDF tools are astounding. In just 3 years of adopting various TF-IDF tools, has increased its organic traffic tenfold. Take a look at our Page 1 keyword ownership over the past 9 years:

After 6 years of flat stagnation, this was a breath of fresh air.

How well does Clearscope work?

One of the easiest and fastest ways to determine if an SEO content writing tool works is to re-optimize a piece of content using the tool’s guidance, then measure the impact after reindexing.

For example, we will take a piece of content that’s already been written and indexed for at least 6 months. At this point, the content is performing as well as it ever will, barring any changes to the on-page SEO, content or link building.

We will plug the piece of content into Clearscope and it will look at the competition’s content and tell us the content gaps we have in our article.

We rewrite the content to address all content gaps suggested by Clearscope, update it in our CMS, then resubmit it to Google. The results of the re-optimization are very fast—sometimes less than 24 hours.

We used this technique on Clearscope and measured the before/after of 3 specific outcomes:

  1. Target keyword ranking position: Each blog we write targets a specific keyword. We measured the keyword ranking before and after re-optimizing the content.
  2. Total clicks: The theory behind re-optimizing content using TF-IDF tools is that you will rank more favorably with your target keyword along with similar variant keywords, thus driving more traffic to the page. By measuring total clicks from search, we can measure the ultimate result of modifying the page.
  1. Total ranking keywords on URL: By writing more thorough content, you will almost always increase the number of variant keywords that your blog ranks for. We measured the number of keywords each blogged ranked for before and after re-optimization.

We did this process with 9 blogs and measured the results from one month prior to publishing compared to one month after re-indexing. They are as follows:

  1. Target keyword position: 56% (5 of 9) increased their target keyword ranking position, 1 stayed the same, and 3 declined slightly.
  2. Total clicks: The 9 blogs increased their click traffic 83.7% on average. 3 blogs more than doubled their traffic, and 1 better than tripled.
  3. Total ranking keywords: The average blog increased its total ranking keywords 81.1%. The highest performing blog increased its total ranking keywords 141% (396 additional keywords).


While I had hoped for stronger target keyword ranking positions, I can’t be too nitpicky because any tool that can boast an 84% average increase in traffic per blog is nothing to snicker at. And the manner in which the tool operates—creating better content by using data—is about as intuitive and white hat as you’re going to find in the industry.

As an added bonus, the tool is designed specifically for content creators so you don’t need an SEO specialist to interpret convoluted data through an overly-complicated UX. As a matter of fact, Clearscope has a Google Doc add-on that allows writers to check their content gaps as they write the content, directly in the doc.

While I certainly can’t comment on which TF-IDF tool works best, as most of those we have used seem to generate strong results, I can say with confidence that Clearscope is one that certainly does work.

Disclaimer: I do not work for, nor do I have any company interest in Clearscope. This test was done out of curiosity in the efficacy of SEO content writing tools.