These are usually single-word keywords with insane amounts of search volume and competition (for example, “insurance” or “vitamins”). Because searcher intent is all over the place (someone searching for “insurance” might be looking for a car insurance quote, a list of life insurance companies or a definition of the word), Head Terms usually don’t convert very well.
Be sure to re-evaluate these keywords every few months -- once a quarter is a good benchmark, but some businesses like to do it even more often than that. As you gain even more authority in the SERPs, you'll find that you can add more and more keywords to your lists to tackle as you work on maintaining your current presence, and then growing in new areas on top of that.
There, now. We’ve given you an overview of twenty-five cool keyword tools. Of course each of these has its own strengths and caveats, and at least for now, none can match the effectiveness of Google’s Keyword Tool, particularly in language, location, or device-specific results. Google gathers and analyzes vast amounts of data and as you know, the rich only get richer.