I am experimenting with my 2 new blogs. One will be "advertised" and the other will be invisible. The antispyware blog is the one I find most interesting. As I find topics and post them, I leave comments on the target site that link back to my blog (if commenting is available). The other one will just get the content. After a few days of minimal work, I have gotten 12 visitors to the antispyware blog and 0 to the other one.
As I am looking for good antispyware content, I find other content relating to spam, antivirus, and security. I am tempted to post links to them to help raise their search rankings. But I am making my blogs to narrow.
Here is one such blog that deserves more attention Ann Elisabeth (spam huntress), she has some excellent blog Spam related posts.