Why use a megaphone in an empty room?

A friend once tried to interest me in blogs. My response was something along the lines of, “Why would I use a megaphone in an empty room?” I suppose I was thinking of blogs in terms of the old BBS days of netmail and forums. I see now that the power of search engines has changed the landscape of electronic communication.

So here I am. Hopefully more than the sound of one hand clapping.