PageRank

Introduction

PageRank is THE original search signal back when Google first started and it is intimately tied up in the Google origin story.

Very briefly, back in the 1997ish, a computer science Ph.D. student was interested in how academic papers have relative values when compared to other academic papers.

A paper had value that was determined by the value of citations to it from other papers, and citations had values determined by the value of the paper they appeared it.

He (Larry Page) and his buddy (Sergey Brin) created a mathematical model of this.

When they tested their model they using webpages and links, people noticed that it produced much better search results than any other search engine in existence at the time.

And thus Google was born.

For what it’s worth, I once downloaded and tried to read the original PageRank patent, but I can’t follow the math, and it was mostly math.

This post is part of a series and here is the link to the main glossary page.

How Page Rank works

While Page Rank is a numerical score between 0 and 10, in the examples below I use 0 to 100 for purposes of illustration.

Let us suppose there is a webpage we’ll call X and it has a value of 60 and two outbound links.

Each link that originates on Page X has a value of 30. The value of each link is 30 because a page value of 60 divided by 2 (one for each link) causes each link to have a value of 30.

The value of page X is created by the links pointing to it. The total value of the incoming links add up to 60, in some combination. It could be one link with a value of 60, 60 links each of which has a value of 1, or any combination in between.

The complexity is in the dynamic nature of it (I think)

What makes the math hard, as I understand it, is that the values of everything are relative to other things and constantly in flux.

Nothing in the world of Page Rank is ever static or absolute.

And Page Rank is why links matter

As you can see from above, the great insight of Page and Brin was to use links as “votes of confidence”. Every link passed Page Rank (link juice, if you will) to the page they linked to, and every page provided value to the links originating from, or anchored on, it.

Which set off an arms race

Which continues to this day.

When people figured out the importance of links to Google rankings, they started gaming the system to create “artificial value” through various means.

And Google and SEOs have been in a bit of an arms race ever since, that continues to this day as we move into the world of generative AI.

Will links always matter?

Probably.

But part of the arms race is that now there is concept of “link quality” or “link appropriateness” which although not rigidly defined (at least outside of Google) in numerical terms, means that for people doing SEO, not all links are treated the same.

But, high quality topically relevant links from the main content of a page (the actual article or blog post, as compared to the side bar, the related posts section, the header, the footer, etc.) will very likely always matter.