If a blog post does not feed back into the blogosphere, that's not blogging. That's merely informative -- or it's the formal learning we did before blogging took hold. If the value of your blogging is not endlessly recursive, then you can conceive of your value like before. If a blog post goes nowhere, that's a web log: an online personal diary.I agree with Tom that the intent of blogging is dialog. If you don't plan to engage with others, then you really aren't having a dialog. On the other hand, you don't necessarily need lots of readers or commentors to get the value. Forcing yourself to formulate thoughts and capture those into written form for public consumption is a great learning vehicle. See some of the dialog in - Top Ten Reasons to Blog and Not to Blog.
Blogging is the repercussions and the reciprocities from responding to responses. That circularity transforms how you are valuable and how you learn. That's what emerges naturally by blogging among us.
Dave Lee expresses some concern that he may not be a blogger because of lack of comments that he receives. But I think you should look at his conclusions, among them:
i've learned more than i'd ever image i could, my writing has improved (it still needs work), and i've connected with some great people i would have never met if it weren't for blogging.
Dave's still not broke down and tried capital letters at the start of his sentences, but, hey, ...