Jackson believes the head of search can improve traffic. For retailers, the tail of search might work best because it targets people searching for a specific product and product model number. For companies focused on "ranking for that one major keyword, having a deep Web site full of great content is necessary to achieve authority in the eyes of the search engine," Jackson writes. "So, even if you didn't intend to do it, you'll be optimizing for the tail in order to achieve your goals for the head."