The need for SEO has become acute in the past few years. Web sites are being created with Java, Flash and images all of which search engines cannot understand and ignore. If the content of your website is ignored by the search engines then they can't index your site, if your site isn't indexed then no one will find your site by searching for it in Google, Yahoo, MSN, etc. If no one can find your site then your hard work and money spent creating the site is in vain.
Site owners started to recognize the value of having their sites highly ranked and visible in search engine results.They also reconised that the higher their site ranking the more people would click on the website. According to industry analyst Danny Sullivan, the earliest known use of the phrase "search engine optimization" was a spam message posted on Usenet on July 26, 1997.