Can't go wrong with the Google Keyword tool, SEMRush and Google Trends. The Keyword tool for volume estimates, SEMRush to see what keywords competitors are ranking for/targeting, and Google Trends to make sure the traffic is actually coming from countries I'm trying to target. Gives a relatively accurate picture of when to expect traffic spikes and seasonality insight.
Well, if you haven’t heard the news yet, the word on the street is Google has shut down their widely popular keyword tool for public use. Now if you want access to Google sanctioned keyword data you have to sign up for an Adwords account. Of course there are a ton of theories surrounding why Google would make this decision, some are more obvious than others. But to many of us Google’s motivations seem pointless when we still have work to do! Luckly we exist in a vibrant industry where innovation is at the core of most of what we do. As such we have a slew of different tools available to replace Google’s tool.

One of the most important aspects of an effective SEO strategy is the ability to research, analyze, and ultimately select the keywords that are most likely to result in success for your clients. There are a variety of free tools available on the web specifically designed to help online marketers do just this. Each tool has its own unique methodology for collecting and presenting this data. Comparing any of the tools’ results without knowing the subtle differences can lead to incorrect inferences and an SEO strategy based on misinformation.

Hi – I’ve read your post with great interest. Not only am I happy for you and your success, it does provide a glimmer of hope to those of us who do have “other” ideas. I, too, have had an idea for a very long time now, but I have no idea how to go about “making it a reality.” I am not a programmer either… though I do know some html… I also remember the old days of having even a web developer holding domains hostage, never mind the site’s entire code. And, yes, that is one of the major things that stops me from even discussing things with a developer. I simply don’t trust them…
If you are somewhat new to this whole ‘make money online’ thing – then surely the cost of Long Tail Pro is a major factor for why you haven’t purchased it yet. Believe me – I know! When I first started out – I refused to pay for anything at all. I did everything the free way. I tried doing all of my keyword research with the free tool that Google provides – and my keyword research efforts were terrible! You know how I know? Because my sites weren’t getting any traffic and I wasn’t making any money.
They also seem to be getting this wrong often enough that I've got less confidence that the keywords that make up these groups really belong there. I recently tried to check the volume for the keyword [active monitoring] (the practice of checking on a network by injecting test traffic and seeing how it's handled, as opposed to passive monitoring) and the Keyword Planner gave me the volume for [activity monitor] (aka Fitbit).
"I've used many keyword tools over the years and Keyword Researcher is up there amongst the most useful of them. Apart from being a great way to get ideas for content, as an AdWords consultant, I also use it to uncover words and phrases that my clients would not want to be bidding on (negative keywords). This is a real time saver for me and a budget enhancer for my clients! All in all, this is a great app and should be used by any professional search engine marketer."
Use the Keyword Planner to flag any terms on your list that have way too little (or way too much) search volume, and don't help you maintain a healthy mix like we talked about above. But before you delete anything, check out their trend history and projections in Google Trends. You can see whether, say, some low-volume terms might actually be something you should invest in now -- and reap the benefits for later.
This is one of the best articles on Keyword research tool that I have encountered. However, To add more to this, I just wanna point out a tool (LSI Graph) for an outstanding long tail & semantic keyword research. After the recent Google algorithm, Google is now, however focussing more on context & semantics than keyword alone. What do you think about it?

Now that I’ve been using Long Tail Pro for several years to successfully find great keywords – I can confidently tell you that Long Tail Pro will more than pay for itself if you use it properly. Whether you are a blogger, a niche site creator, an affiliate marketer or even just an article writer – doing proper keyword research will help you be more profitable. Doing proper and effective keyword research with Long Tail Pro is super fast and easy. It’s so easy in fact – that it’s not hard at all to offset the cost of the software by putting it to work for you. And I’m going to show you how within this post.

The final sales price was based on a multiple of trailing 12 months net income (i.e. The average net income over the most recent 12 months).  I feel like I got a very good multiple.  I had talked to the brokers at FEinternational, Quiet Light Brokerage, and had viewed sale history of other similar companies, so I know the price I received was very competitive.