Well, that depends on how you look at it. There are plenty of users on HubPages who have become financially successful at the online writing game. And there are others who have developed large followings and high search rankings. But if you are referring to success outside of HubPages, we can't really know for sure. For example, I'm writing a book that I will try to get published next year. If I'm successful, I'll probably still use my HubPages account as a side source of income. I will not, however, identify myself as that author. I feel the two are independent of each other, and I would just be restricted if I had to watch what I say for fear of offending fans. So if there are successful writers here on HubPages, they probably wouldn't admit it outright (or they don't think it's relevant information).