Mark Hinkle has been the editor in chief of two industry trade publications and a blogger for nearly five years. He recently posted an amazingly comprehensive guide for PR people who want to reach out to influential blogs called PR Tip: How to Pitch a Blogger.
I agree with all of Mark's suggestions. Like Mark, I also get hundreds of unsolicited press releases and PR pitches each week and I can say that 99 percent of them suck. Worse, some are so poorly written as to harm the reputation of the company (or agency) that sent it. Unfortunately, most are just spam.
I would add a tip of my own to Mark's list: Don't tell us what your product does (that’s boring and usually just goes down a rat hole of gobbledygook). Instead, tell us how your company solves problems for your customers.
If you're in PR and are trying to get your company (or your clients) noticed by bloggers, read Mark's post.