One possible problem is that although the Keyword Planner has some cool new features (including integration of the Google Traffic Estimator, which will be retired too), as of this writing, the indispensable Exact Match and Phrase Match features are nowhere to be found! Whole books will become useless without these, so I hope Google will eventually port them to the Keyword Planner. Nor do you see the “Include specific content” option, which is a life-saver for the adult industry, which spends the most on Google PPC.
While this one isn’t necessarily a keyword research tool, it will give you valuable insight into how the keywords you’ve been optimizing for so far are actually performing for you. You might realize that you could start ranking for more keywords with more difficult competition, for example, or that only keywords on certain subjects are working for you.
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?
This tool was originally created to carry out keyword research for paid campaigns using Google's AdWords platform. However, it can also be used to research organic keywords, providing estimated global/local monthly search volumes for keywords (i.e. their popularity) and their competition (i.e. how difficult they are to rank for) for organic search.
The cost is only a one time payment…no monthly fees, which is fantastic if you’re on a budget, and you get lifetime updates and some truly excellent training videos as well as some very useful built-in tools. I’ve also tried other paid keyword tools such as Market Samurai, Wordtracker, Jaaxy, and others, and let me tell you this….none of them come close to Keyword Researcher Pro for value and ease of use.

The simplest KW research tool is google. Type in your topic and scroll to the bottom to see what related results show up. Use those to either write an article or to supplement other articles with some of the keywords. Yes, they are primary phrases so you may not rank for them right away but building your site with these in it will help get rank for them eventually. Also look at what other articles that show up for the keyword use.
The “Starter” tier, with 1000 keyword lookups every 24 hours should be enough for anyone starting out in blogging – or even people who are quite established. It’s pleasing to see a product where they don’t seem to trick you into having to pay for a more expensive version. On the more negative side, I did feel that you’re nudged towards doing annual payment, with the monthly option kept slightly “hidden.”

Hey Alex – this is a good question. No tool is going to be spot on. My advice is to not look too much into the accuracy of the metrics, but look at it more as a relative measure. I’m finding Ahrefs to be a good barometer for keyword competitiveness, but I’ve also heard great things about KW Finder lately. I think it’ll more come to personal preference. Both are solid options.
As for the history of the company, as I explained, I created Long Tail Pro back in 2011.  At the time, I was creating tons of niche sites and was doing alot of keyword research and content creation.  I was trying to figure out what types of keywords would rank quickly in the search engines, specifically Google, and I was frustrated with the other keyword research tools (in particular Market Samurai) out there.