I write a lot, but I don't blog. The people I write for don't use RSS feeds or routinely scan a large number of sites, and I'm not prolific enough on any one topic to give anyone incentive to follow my blog, since I don't have any friends that share more than one or two of my interests.
When I write about food and recipes, I send an email to three or four people I know will be interested. When I write about a backpacking or travel destination, it's an email to a different handful of people. When I write about exercise, I put it on a private blog where I record my food, exercise, and weight every day. When I write about software, I usually throw it away, though I often find an opportunity to recycle the thoughts and language in a discussion online or in person. When I write about a book, I share what I've learned by talking to a friend who would be interested. Et cetera.
I've thought about putting everything on a blog and just sending links to people when there's an entry they'd be interested in, but writing a blog that has no consistent readership and constantly bugging people to read it just feels pathetic for some reason.