By "personal site" is meant, in most cases, an online CV, in which are presented and detailed activities, skills, involvement in different projects, an image gallery (photo-portfolio) and why not, a meeting place with friends, colleagues, relatives or people who share the same thoughts as you.
A properly designed web site will increase notoriety and popularity. Think about what it means for an Internet user to discover your site in a context that you promote or represent, by certain keywords. Think about how good it is for your business and image for a visitor to come to the site and discover new things that are reflected in the site, and you control who they are.