When you have run out of ideas for keywords to target in your next pay per click advertising campaign, try using Google’s Search-Based Keyword Tool. This tool will analyze your website to find new keywords that you are not targeting. You type in the specific web page that you want to analyze then add your most important keywords and the keyword tool does the rest. It will return a list of keywords, albeit a small list, though it will inform you of keywords that you may not have thought of. On the other hand, every keyword could be one you’ve already got in your pay per click campaign.
What this tool is designed to help you do is find those missed opportunities that you can capitalize on. The best use of the search-based keyword tool that I’ve found is to type in the URL of your landing page and the five most important keywords for that page. If you find one or two more keywords on your returned list that are not a part of your campaign, add them to your keyword group and see what happens.