Google Wonderwheel
Picking SEO Keywords: Using Google’s Wonder Wheel
This is the best little secret of everyone’s favorite search engine: called Google Wonder Wheel. Released about a year ago but virtually unknown compared with Google’s much more visible search tools, the Wonder Wheel can be accessed by doing a search and then selecting “Wonder Wheel” under the filter options on the lefthand navigation.
What you are presented with now is a visual representation of the way that Google groups together keywords. (Indirectly, you can also deduce how users themselves perceive search terms.) This alone can become the basis of your PPC and SEO keyword research.
Starting with the search term dog food, I see related more specific terms like dog food reviews, dog food comparison, and dog food brands, which can help identify other keywords to focus on. Then, clicking on dog food brands, the search engine automatically expands that keyword to be another hub, with more specific keywords related to dog food brands such as pedigree chum dog food,  and so on.
You can use this tool to help shape overall content strategies. Continuing with the dog food example, we can see that ratings, comparison, and reviews all were all grouped as closely related to dog food in general, implying that people that are searching for dog food are very interested in the comparison and review side of things. So from a content strategy perspective, it would be a very powerful takeaway to include a heavy emphasis on customer ratings, third-party reviews, and side by side comparisons to help the consumers make their dog food selections while shopping on our site.