PageRank and SEO

Thanks (or no thanks) to the fact that most search engines’ techniques are trade secrets, SEO is made more difficult. There is a whole industry dedicated to SEO and to finding ways to outsmart, outwit, and out-search the competition; to (legally) manipulate search engines to get the top spots in search results. Top search results = instant visibility in searches = more clicks and visits = more customers = more revenue.

Obviously, the final arbiters in the SEO battle are the search engines themselves. After all, SEO aims to optimize sites for better rankings on search engines. Of all the currently available search engines, Google has become the most popular, eclipsing all others that came before it such as Yahoo!, Excite, Lycos, and Altavista – truly a case of the-upstart-new-kid-who-got-all-the-babes sort of thing. As a result of Google’s popularity (and the fact that some other search engines actually use Google for their searches), SEO experts tend to optimize according to Google’s rules.

What makes Google so popular? One reason would be Google’s approach of presenting an uncluttered web interface. Such an interface has proven to load pages faster, present fewer distractions, and be more concise. It should be known that Google was not the first to use a minimalist user interface; early Altavista used to do the same thing (actually, it still does today).

A more important reason for Google’s popularity would be its ranking system called PageRank. PageRank, or PR for short, consists of a set of algorithms and mathematical formulas for computing and assigning numerical rankings for all webpages. A patent was awarded in 2001 for the PageRank invention.

The essence of PageRank is the premise that any given webpage with many other webpages linking to it for a specific set of keywords must truly be relevant to searches for those keywords. Each incoming link to a page is a vote for that page’s relevance and usefulness. Hence, more incoming links equals more relevance.

Without getting into the math, consider an example of four webpages: W, X, Y, and Z. If X, Y, and Z all link to W, it should be obvious that W is really a relevant page. Whatever subject matter page W contained, W would come up as the first, or top, in the search results for that particular subject or topic. Stated in general, the PageRank of a certain page W is the sum of the PageRank values of all the pages that point to it for a given set of keywords. This generalization also implies that when computing the PageRank of a particular page, incoming links from pages with high PageRank values are given more weight than normal. PageRank values are simple numerical values on a scale of zero to 10, with 0 being the lowest and 10 being the highest or heaviest rank.

That is only as far as Google makes the workings of their PageRank algorithm known. According to Google, other text processing and matching techniques are used to further validate PageRank assignments for webpages, going beyond ordinary assignment based on keyword frequency. These are kept secret. Yet, in an age of search engine wars, where mostly everything is secret and shrouded in mystery, it is an interesting twist that Google has made known some details of PageRank.

What does this all mean for SEO? Because PageRank works on a site’s incoming links to determine its importance, SEO firms, experts and professionals are concerned with increasing links to their sites. Currently, there is only one accepted true ethical way to do that: by providing high quality content that sites would voluntarily link to.

Okay, so that is fine and dandy in a perfect world. But the world is not perfect, and neither is the World Wide Web. In this world, money talks, and money has been used to buy links from sites to artificially and unfairly boost a site’s rankings in search engine results. Unfortunately, PageRank is not impervious to such machinations. Until search engines evolve from using keyword-based searches to some new, undiscovered way to search, we can expect keyword abuse. Fortunately, PageRank is in a constant flux, constantly adapting to new forms of link spamming, and Google heavily penalizes sites that cheat for PageRank.

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