The quality of visitor traffic to a site can be measured by analyzing how often a visitor who uses a specific keyword phrase in a search actually performs what is known as a “conversion action.” That is, how often those visitors make a purchase, download materials, request information, or interact with the site in any other way that indicates interest in the product or service the site offers.

Simply put, SEO is marketing through an understanding of how search algorithms work combined with a knowledge of what human users might search for. The end goal is to create a site that contains words for which people will likely search when looking for information such as that contained on your site.