All Links Are Not Created Equal

[djbaxter]

All Links are Not Created Equal: 10 Illustrations on Search Engines' Valuation of Links
by Rand Fishkin
May 27th, 2010

In 1997, Google's founders created an algorithmic method to determine importance and popularity based on several key principles:

• Links on the web can be interpreted as votes that are cast by the source for the target
• All votes are, initially, considered equal
• Over the course of executing the algorithm on a link graph, pages which receive more votes become more important
• More important pages cast more important votes
• The votes a page can cast are a function of that page's importance, divided by the number of votes/links it casts

That algorithm, of course, was PageRank, and it changed the course of web search, providing tremendous value to Google's early efforts around quality and relevancy in results. As knowledge of PageRank spread, those with a vested interest in influencing the search rankings (SEOs) found ways to leverage this information for their websites and pages.

But, Google didn't stand still or rest on their laurels in the field of link analysis. They innovated, leveraging signals like anchor text, trust, hubs & authorities, topic modeling and even human activity to influence the weight a link might carry. Yet, unfortunately, many in the SEO field are still unaware of these changes and how they impact external marketing and link acquisition best practices.

In this post, I'm going to walk through ten principles of link valuation that can be observed, tested and, in some cases, have been patented. I'd like to extend special thanks to Bill Slawski from SEO By the Sea, whose recent posts on Google's Reasonable Surfer Model and What Makes a Good Seed Site for Search Engine Web Crawls? were catalysts (and sources) for this post.

Read more...

 

[harold15]

Well, I think the point of this post is very clear. If you get a link from a page which has a decent level of authority and trust in the sight of Google, it'll not carry the same weight as getting a link from a low quality site.