A successful WordPress blog or site is one that insinuates itself into the fabric of the Web really well. It contributes to the rich tapestry of interlinked blogs, sites, and social media, and becomes part and parcel of daily life in its particular niche. A good site does not standalone. Instead, it provides a platform for people to find information, become engaged, or be entertained.
Using WordPress gives you a competitive advantage because you can spend more time focusing on creating content and marketing your ideas, products, or services without having to learn how to be a competent programmer.
This is important because there is a complex web of relationships, competition, and creativity that goes into carving out a niche. You will compete directly with some people, collaborate with others, teach still more and, hopefully, learn from others at the same time. In particular, a blog from WordPress.com makes it very easy to engage with your niche because it comes ready-made with virtually everything a modern site needs—including a large and active community of bloggers.
In any given niche, there are already established players, newbies, spammers, bloggers, forums, wannabies, and so on. Much about online success or failure comes down to the art of dealing with these different people in a variety of different settings because it is these people who may ultimately recommend or shun you and have a direct bearing on your success or failure.