The key to successful of blogging is somebody love something irrationally beyond the point and just want to own that topic and when somebody have that kind of passion of what they love, it can be intrested in the topic and i think that really passionately. the single subject blogs have seen that are amazing like history of person which can be better record which never heard and they can tell us story about why they are important while comparing with you. i think blog people discover like news, culture, sports, entertainment, media as well as personal blog which passion about things like hobby and area of expertise, they know better than anybody else those people i feel can become famous blogger.