With so many people writing online today, just appealing to the robots is a surefire way to never gain market-share. Keyword research is important for creating targeted content, but focusing on things like keyword density leads to dense sounding content. And nobody wants to read that!
Even if your content exactly matches a search query, Google is not going to trust it much unless other people trust it first, which leads to a chicken vs egg scenario.
Until you get subscribers, build market attention, and people regularly link at your writing, then it is important to put people well ahead of search engines. When writing your headlines make sure they are clear and compelling, but place human emotional response ahead of trying to match as many keyword phrases as possible.
If you are new don’t be afraid to ask for help with marketing. Write comments on popular blogs, participate in discussion forums, buy AdSense ads on related blogs, interview someone who is popular or blog about them. Eventually people will notice. We are all selfish. We are each the most relevant thing in our lives.
Read more of Aaron’s work at his SEO Book Blog.