When first setting up a campaign using Google AdWords, turn off the content network. It’s a form of contextual advertising and tries to position your ads on sites like About.com, The New York Times and others. You typically will see high impressions in your system, but often low click-through-rates, as determined by impressions to clicks–and low-quality clicks. These aren’t serious buyers; they’re wasting your dollars and time.
Analyze your competitors. One way is to use the Google Keyword Tool. Select “site-related keywords” and enter the competitor’s website to pull keyword groups from their pages. Also, check their sites for an overall impression and for content. Link.