Once I have a list of phrases, rankings, and volumes from these tools, I'll look to internal tools (maybe Excel, Access, or another database) to organize, classify, and forecast opportunity. This is where I'll estimate a competitor's traffic based on volume & position CTR, set goals for a target position, and estimate traffic based off that position's CTR and keyword volume.
Keyword Discovery is a paid subscription service that offers marketers the ability to see keyword data across multiple search engines. They maintain one of the largest databases of searches, (nearly 38 billion) which are compiled from over 50 different search engines. The search data shown is a record of the number of times the exact keyword or phrase has been searched over the last 12 months across all 50+ search engines. You would assume that the search volumes would be much larger than any other tool because of Keyword Discovery’s access to data from over 50 search engines, but the fact that the keyword matching option is set to exact, greatly reduces the total volume. Unlike Google’s tools, Keyword Discovery does not collect or show data relating to paid search, such as Suggested Bid, Cost per Click, and Competition. Data is collected daily, but updated monthly. Although you must pay the subscription to have access to all the features, Keyword Discovery does provide a free alternative.
But it’s still very useful for getting search volume data (provided your account still shows this), which is helpful when choosing which of the many keywords you’ve found to focus on (although you should take these estimates with a pinch of salt, they are still useful in indicating the relative search volumes of different keywords, even if the absolute estimates are a little off).
To answer your final question, yes but not really. You can definitely use AdWord keyword planner tool to get solid organic search volume estimates. However, don’t just stop there. Leverage other tools to find longer tail variations you can map against various stages of the buyer journey. I like to use SEMrush, Keyword Tool.io and Google autosuggest.
"Our whole team has a copy of Keyword Researcher, we use it for everyone of our client's keyword research for the 'Long Tail' and we use it every day to come up with blog post ideas and ideas for guest posting. We couldn't live without this tool. I have used every paid keyword research tool under the sun, and this by far is my favorite tool for mining the Long Tail."