Blogging about someone famous in a region is definitely one of the most niche blogging topics today. A person who is regionally famous is someone who has a very prominent profile among public in that region and commands some decent degree of public fascination and influence in day-to-day regional media. This term is often synonymous with wealth (commonly denoted as a person with fame and fortune), working for social or regional causes, implied with great power or popular regional appeal, prominence in a particular field or many fields, and is easily recognized by the general public in that region.
Regionally famous status is commonly associated with various careers within the fields of social service, administration, niche education, sports and entertainment; These fields have often produced prominent figures within many regions.
While people may gain regionally famous status as a result of a successful career in a particular field (primarily in the areas pertaining towards education, social service, administration, sports and entertainment media), in other cases, people become popular due to media attention for their extravagant or flamboyant lifestyle or wealth (as in the case of a socialite); for their connection to another famous person in that region(as in the case of a relative or friend of a famous person in that region); or even for their misdeeds (as in the case of well-known and notorious criminals).
Regionally famous people may also be known around the world (e.g., pop stars and movie actors), within a specific country (e.g., a top Soccer player, a minister, social wellfare worked); or within a region (e.g., a city administrator, mayor, socialite, news editor of a regionaly daily, local television channel news anchor).
People local to a region often try to follow the happenings in the life of regionally famous personalities and try to imitate their style or deeds and read dedicated blogs online to find information about these people. Blogging either about single or multiple regionally famous personalities is definitely going to spur a lot of interest in readers from that region and thus bring in more people onto your blog.