Does Writing Make a Writer?

If I write a blog, and no one ever reads it, does it really exist? This is a question that can be asked about a lot of things on the Internet. Of course, technically, if even one person can access it, it really exists. But does it make a difference? Does it accomplish what the writer intended for it to? Which brings me to another question? Why do people write blogs? If it's just to keep a journal, anyone can do that with pen and paper, or on one's own computer. Why does it need to be on the Internet? What difference does it make if it's "out there" or not? Are all of us hoping to be "discovered"? If so, by whom? So, why do we write? Who do we write for? Who do I picture as reading this as I'm writing it, or am I only writing for myself?

This is the same issue that comes up about being a writer in the first place. Can you consider yourself a writer if no one but you ever sees what you write? Conversely, if others do read your writings does that make you a writer?