Twenty-two years ago, the founders of Google invented PageRank, and forever changed the web. A few things that made PageRank dramatically different from existing ranking algorithms:
- Links on the web count as votes. Initially, all votes are equal.
- Pages which receive more votes become more important (and rank higher.)
- More important pages cast more important votes.
But Google didn't stop there: they innovated with anchor text, topic-modeling, content analysis, trust signals, user engagement, and more to deliver better and better results.
Links are no longer equal. Not by a long shot.
Rand Fishkin published the original version[1] of this post in 2010—and to be honest, it rocked our world. Parts of his original have been heavily borrowed here, and Rand graciously consulted on this update.
In this post, we'll walk you through 20 principles of link valuation that have been observed and tested by SEOs. In some cases, they have been confirmed by Google, while others have been patented. Please note that these are not hard and fast rules, but principles that interplay with one another. A burst of fresh link can often outweigh powerful links, spam links can blunt the effect of fresh links, etc.
We strongly encourage you to test these yourselves. To quote Rand, "Nothing is better for learning SEO than going out and experimenting in the wild."
1. Links From Popular Pages Cast More Powerful Votes
Let’s begin with a foundational principle. This concept formed the basis of Google’s original PageRank patent, and quickly help vault it to the most popular search engine in the world.
PageRank can become incredibly complex very quickly—but to oversimplify—the more votes (links) a page has pointed to it, the more