Search Engine Ranking Factors
The algorithms used by Google, Yahoo!, or MSN Live Search to calculate search results can change at
any time, therefore we generally avoid citing specific details regarding particular search engines and
their algorithms. Search engines have been known to occasionally modify their algorithms and, as a
result, turn the SERPs upside down. Examples of this include Google’s Florida and BigDaddy updates.
A great place to peruse to see the latest trends are the forums mentioned at the end of this chapter.
Historically, search engine marketers created optimized pages for each particular search engine. This
is no longer viable, as mentioned in Chapter 1, because it yields duplicate content. Rankings must be
achieved in all search engines using the same web pages. Furthermore, calculations such as “optimal
keyword density” and “optimal page content length” for the various search engines are almost entirely
obsolete. Calculations like these demonstrate a gross oversimplification of modern search engine infor-
mation retrieval algorithms.
With these disclaimers out of the way, it is time to briefly discuss the most important and consistently
considered factors as a quick primer for the web site developer. We group the factors that affect search
engine rankings into the following general categories:
Visible on-page factors
Invisible on-page factors
On-page factors are those criteria of a web page that are dictated by the contents of a web page itself.
They are critical to a search engine marketing campaign, but less so than they were historically, because
they are very easy to manipulate. Because there are obvious incentives for spammers to do so, search
engines have begun to place importance on other factors as well. That is
to say that on-page factors
are not important, however.
It is useful to further divide on-page factors into two categories — those that are visible and those that
are invisible. The former are much more important than the latter. Many search engine marketers
believe that the latter are now devalued to the extent that they are mostly not worth bothering with.
This is because they can be so easily manipulated without influencing page presentation at all. Spam
can be carefully hidden in a web page in this way. A search engine’s confidence in such factors being
honest or accurate, therefore, is low. In short, the search engine’s algorithms regard visible content
with more confidence, because the user will actually see this content.
Any content that is hidden using CSS or other forms of subterfuge, regardless of intent, may be regarded
as an invisible factor and devalued. At worst, if employed excessively, the page or site may be penalized as
You can find a great synopsis of the relevance of the various factors, in the opinion
of a number of various experts, at
Chapter 2: A Primer in Basic SEO
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