But Google’s web crawler and PageRank algorithm were
revolutionary for information retrieval.
Google looked at both on-page and off-page factors – the quantity
and quality of external links pointing to a website (as well as the
anchor text used).
If you think about it, Google’s algorithm was essentially about “if
people are talking about you, you must be important.”
Although links were only one component of Google’s overall ranking
algorithm, SEO practitioners latched onto links as being the most
important factor – and an entire sub-industry of link building was
created.
Over the next decade, it became a race to acquire as many links as
possible in the hopes of ranking higher.
Links became a heavily abused tactic that Google would have to
address in coming years.
It was also in 2000 that the Google Toolbar became available on
Internet Explorer, allowing SEO practitioners to see their PageRank
score (a number between 0-10).
This ushered in an era of unsolicited link exchange request emails.
So with PageRank, Google essentially introduced a measure of
20 YEARS OF SEO: A BRIEF HISTORY OF SEARCH ENGINE OPTIMIZATION