A History of SEO
The competing interests of search engines and black hat Search Engine Optimization (SEO) have contributed to the evolution of popular search engines like Google since the 1990's. The company now has proactive measures in their algorithm to filter out poor quality content such as link building, spamming and link baiting. Heavy penalties, the emergence of social proof, highly advanced web crawlers and human editorial have evolved over time to prevent poor quality SEO.
Some of the earliest search engines like Archie Query Form could only look at the text on websites to understand which websites should rank higher. Early SEO was the practice of repeating similar keywords repetitively to become the highest ranking on a search engine. Search engines started improving their algorithms by using keyword density, header tags and word counts to rank websites in the late 1990s.
Google was the first search engine to use inbound links as a ranking signal and editorial vote of confidence in the late 1990's. Unfortunately, the buying and selling of text link ads attracted poorly written articles, blogs, and website spam. From 2003 Google started to penalize the practice of buying and selling of inbound links. Editorial processes were also introduced in 2006 and websites were rated by how well they followed Google's quality guidelines. A dramatic decrease in black hat SEO was the result.
Google became more personalized with the introduction of Google + and refinement of local search results from 2011 onward. The thinning out of content farms and low-quality websites resulted from the Panda update in 2011 and the Penguin update decreased keyword targeting and unnatural links from 2012.
The current SEO environment has made it difficult for black hat SEO. Content must pass Google's stringent quality, trust and authorship guidelines or risk being penalized. Engagement, relevance and social proof are essential for quality SEO and website owners are now more reliant on complex social relationships to improve the trust and quality of content.