These 3 keyword matching options are not solely to blame for the large variations seen when comparing data from the keyword tools. Much of this difference can be attributed to the distinctive techniques that the tools use to collect their data. Let’s take a look at how these tools collect and present their data and hopefully it will help clear up any confusion.
"This tool is simply Amazing. I've been uncovering literally thousands of highly related keywords for my clients websites, with this tool new content ideas have become a breeze. I literally have hundreds of new ideas for articles to write about for my sites and my clients sites. The Keyword Researcher tool was truly a great buy for my business and I highly recommend it to anyone."
Joost developed his own keyword research tool to come up with keywords as well! Yoast Suggests uses the Google Suggest functionality you know from searching in Google. It finds the keyword expansions Google gives and then requests more of them. So if you type ‘example‘, it’ll also give you the expansions for ‘example a…’ till ‘example z…’ etc. Just go on and try it and fill out some of your potential keywords. It’s a great way to quickly find more long tail keywords you can focus on.
This isn’t the only tool that mines Google Autocomplete. There’s also, but this tool restricts results to ~700 keywords (more are available for “pro” members). Infinite Suggest is another alternative, but despite the name, I’ve found that it still doesn’t find anywhere near the number of keywords that Keyword Shitter finds. And there are tons of other Google Autocomplete miners too. Just Google “google auto suggest tool” for more. There’s also this tool from SEOChat which mines autocomplete suggestions from Google, Bing, Amazon, and YouTube.
Here’s where this tool’s value really comes in: Keyword Tool has keyword research tools for multiple search engines, not just Google. If you want to do keyword research for YouTube, Bing, Amazon, the App Store, or eBay, they’ve got keyword suggestions (and data) for you. If YouTube videos, for example, are a central part of your marketing strategy, this could easily be worth the money.

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.
TIP: A really good strategy for increasing your search engine rankings (and maybe even getting a featured snippet), is to pick a number of popular questions, and answer them in your content. You can do this in the form of a ‘Question & Answer’ section or maybe ‘FAQs’. Just pick half a dozen or so questions, and list them, together with a short answer.
Note: the old software version of Long Tail Pro would have spit out several hundred adwords suggestions (many being irrelevant to the seed keyword) for this one seed keyword and then you would have to filter to see only what you wanted to see. With the new cloud version of Long Tail Pro, you set it to show only a certain number of keywords and it displays the most relevant keywords so you have less noise and confusion to filter through.
Keyword everywhere is another useful keyword tool. You can install it on either Firefox or Google Chrome. The tool will be able to show you competition data, cost per click, and Google Keyword search volume of multiple websites and keywords. This free extension can help you to save a lot of time. It can assist you to find long-tail phrases including their precise search volume, competition data, and CPC.
It would be great if you can provide comparative analysis of this tool with Google Keyword Planner. Since you’re using this tool so you can provide best comparison. One differentiation which I understood is that this tool works for yahoo and bing as well whereas Google keyword planner works only for Google but Google being a dominating search engine, gives the highest returns, so only this reason may not be enough to buy it.