Every now and then I learn who is reading--has been reading for a long while--my blog, and I'm delighted, each time. I meet people this way, not just on line, but in the flesh. Way, way cool.
I believe in the blogosphere. I don't think it's difficult to find the gems amidst the junk. I think it's an evolving form of epistolary writing; it's also a form which allows us to learn HOW to write by giving us incentive to write well while not obviously punishing us for writing badly.... Yes, there lurk plenty of scolds among blog readers, but most of them are crackpots and easy to ignore (unless they're correcting your grammer--oops, Fred, did I just call you a "crackpot?") And the more positive-minded readers tend to come up to you in bars and confess their fondness.
I recommend it. Start a blog. Write a letter to all your (unknown) friends. Trust me, it's appreciated, at least by me.