With millions of people performing millions of searches each day to find content on the Internet, it makes sense that marketers want their products to be found by potential consumers. Search engines use closely guarded algorithms to determine the results that are displayed. However, determining what factors these algorithms take into account has led to a growing practice known as search engine optimization.
Search engine optimization (SEO) is the practice of optimizing a Web site so as to achieve preferred ranking on the search engine results pages (SERPs). Someone who practices SEO professionally is also known as an SEO (search engine optimizer).
SEO can be split into two distinct camps: white-hat SEO and black-hat SEO (with some grey-hat wearers in between). Black-hat SEO refers to trying to game the search engines. These SEOs use dubious means to achieve high rankings, and their Web sites are occasionally blacklisted by the search engines. White-hat SEO, on the other hand, refers to working within the parameters set by search engines to optimize a Web site for better user experience. Search engines want to send users to the Web site that is most suited to their needs, so white-hat SEO should ensure that users can find what they are looking for.
By the mid-1990s, Webmasters had begun to optimize their sites for search engines due to a growing awareness of the importance of being listed by the various engines. Initially, all a Webmaster needed to do was submit the URL (uniform resource locator) of a Web page for it to be indexed. Search engines relied on the metadata, information that Webmasters inserted in the code of a Web page, to determine what a Web page was about and to index it appropriately.
Industry analyst Danny Sullivan records that the earliest known use of the term “search engine optimization” was a spam message posted on Usenet, an online forum or message board, on July 26, 1997.Danny Sullivan, “Who Invented the Term ‘Search Engine Optimization’?” Search Engine Watch, June 14, 2004, http://forums.searchenginewatch.com/showpost.php?p=2119&postcount=10 (accessed June 6, 2008).
Realizing the importance of being ranked highly in search results, Webmasters began using the search engine’s reliance on metadata to manipulate the ranking for their Web sites. To combat this, search engines in turn have developed more complex algorithms including a number of other ranking factors.
While at Stanford University, Larry Page and Sergey Brin developed a search engine, called Backrub, that relied on a mathematical algorithm to rank Web pages. This was the precursor to Google. They founded Google in 1998, which relied on PageRank and hyperlink analysis as well as on-page factors to determine the prominence of a Web page. This enabled Google to avoid the same kind of manipulation of on-page factors to determine ranking.
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page’s value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. But Google looks at more than the sheer volume of votes, or links a page receives; it also analyzes the page that casts the vote. Votes cast by pages that are themselves “important” weigh more heavily and help to make other pages “important.”“Understanding Google Page Rank,” Accu Web Hosting, May 20, 2006, http://www.accuwebhosting.com/Articles/Understanding_Google_Page_Rank.html (accessed June 18, 2010).
PageRank was based on the practice of academic citations. The more times an academic paper is cited, the more likely it is an authority paper on the subject. Page and Brin used a similar theory for their search engine—the more times a Web page or Web site is linked to, the more likely it is that the community considers that page an authority. It should be noted that the importance of page rank has been greatly reduced over the years.
Ranking highly in search results is vital to Web sites, so Webmasters have adapted as search engines have updated their algorithms to avoid being “gamed.” Today, Google says it uses more than two hundred different factors in its algorithm (which changes over four hundred times yearly) to determine relevance and ranking. None of the major search engines disclose the elements they use to rank pages, but there are many SEO practitioners who spend time analyzing patent applications to try to determine what these are.