Search engine optimization, or SEO, is the practice of creating and modifying web pages and web content so that they rank higher on search engine results. Successful SEO practices can make a website more visible to relevant search engine users, thus earning that site increased quality organic traffic. SEO began in the mid 1990s, and the way that it is conducted has evolved parallel to search engine ranking methods.
Early Days of SEO
The actual term "SEO" first came to use in 1997, according to industry analyst Danny Sullivan. But even a couple years before that, webmasters and online content providers were already testing out ways of manipulating keyword density and placement in order to rank higher in the results pages of the internet's early search engines.
At that time, one only had to submit one's web address or URL to the search engines and they (the search engines) would send spiders to crawl through and index one's site. As soon as people realized how lucrative it could be to have your site listed on the first page of search engine results, they started looking for ways of manipulating search engine algorithms.
The Problems of Early Search Engines
Before 1998, the year Google entered the scene, search engine ranking algorithms only looked at on-site information to determine ranking, which meant information that was directly provided by webmasters. All you needed to do to get on the first page of AltaVista results was to put the right keyword tags in the right density in the right places, and that was it. Unscrupulous webmasters also started to manipulate HTML source attributes to get higher rankings. This led to results being filled with spam pages, whose keyword tags did not match up to the page's actual content.
In 1997, the first algorithm crackers started working on decoding search engine algorithms. This same year, several SEO's managed to decode all 35 parameters of Excite's algorithm.
Relying heavily on on-site factors that could be easily manipulated by webmasters and content provider had gotten search engines in trouble. To try to bounce back, search engines developed more complex algorithms that took into account off-site factors that could not be as easily manipulated. Things like links and directory age. SEO and algorithm cracking becomes harder and more specialized.
But despite improved algorithms, black hat SEO providers were still finding ways to spam results pages. In 1998 Google was founded by Stanford grad students Larry Page and Sergey Brin and their new page raking algorithm immediately caught the attention of the other major search engines. Google's PageRank measured a site's quantity and quality of inbound links to determine ranking. Other search engines follow Google's lead.
By 2001, search engines start to steadily fall off the radar, as user abandon sites like Lycos, Excite and AltaVista in mass numbers and instead flock to the more consistently reliable results of Google Search.
The Age of Google
In 2004, there were only three major search engines drawing most of the internet's search engine users, and Google was already pulling ahead and showing no signs of stopping. Search engines start incorporating more complex factors into their page ranking algorithms. Keyword spamming SEO is effectively over, in terms of long-term, reliable search engine results improvements. Social media and off-site SEO efforts become crucial.
In 2005, Google started customizing individual search results according to user history. In 2007 Google began campaigning against paid links, and in 2009, the company started trying to combat the effects of Page Rank sculpting by the use of nofollow links.
Today, Houston, TX SEO providers' marketing strategies revolve around adapting to Google's PageRank algorithm. Google dominates over 70% of the search engine user market, and is thus the place where you have to improve your rankings if you want to see increased organic traffic. SEOs now must provide not just keyword density but something that must actually approach the level of real, relevant value in order to rank higher for targeted search terms.