The practice of search engine optimization first came into being in the mid 1990s when the first search engines began cataloguing the contents of the Internet. Initially the entire procedure was fairly honest and a fair reflection of what content there was on the web. Sites were submitted to the search engines and a spider crawled the content and then stored the collected data in a database that could be accessed by individuals performing a search.

When a search engine spider detects new content on the Internet it downloads a page where it is stored on the engine's own server. Once on the server a second program, known as indexer extract information about the page as well as all of the links it contains. This page is then placed into a depository of pages to be crawled at a later date.

At first, the information that ended up on these early search engines came from the webmasters who were trusted to be honest. Early versions of search algorithms relied on webmaster-provided information such as the keyword meta tag, or index files in engines like ALIWEB. Meta-tags provided a guide to each page's content. However the corruption of this system began when webmasters abused meta tags by including keywords that had nothing to do with the content of their pages, to artificially increase page impressions for their Website. This of course also increased their ad revenue from pay per clicks and costs per impressions. Greed soon led to inaccurate, incomplete cataloguing of web pages and too many people being led to pages without content or with misleading content when they conducted a web search. Search engines responded by developing more complex ranking algorithms with the result that understanding SEO has become much more complicated then it ever has been before and will continue to become more complicated.