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 keyword research tool is effective, automatically providing you with keyword suggestions that other sites haven’t necessarily turned up (which it’s intended to do), along with their search volume, CPC, and Adwords competition. In order to get any actual information about the keywords, though, you need to upgrade to Keyword Tool Pro (which is a little misleading on the site copy). This plan is $88 a month, and if you’re just doing keyword research for Google, I’d recommend choosing one of the other tools for the price.
I’d give Long Tail Pro a 4.5/5 stars for its’ ease of use, ability to generate a high number of long tail keyword searches of low to medium competition, check rankings and check Top 10 competition on any keyword search as to what the results of number of backlinks, domain authority/page authority and other pertinent ranking data from Moz.com’s api.
I’ve found google trends to be an interesting way to see if a keyword (and by extension a niche) is growing or shrinking, and whether it’s seasonal or not. I can’t think of any other tool out there that can reliably tell you this information, so that’s really useful. Also, if you’re building a site, especially an authority site, getting onto something that’s trending upwards is a fantastic idea.
Long Tail Pro is a keyword research tool that helps you quickly find low competition keywords for your website. In particular, the tool is built for people doing SEO (search engine optimization) as opposed to people doing paid ads (Google Adwords PPC). I'm sure there are some advertisers that use the tool for paid ad keyword research, but the tool was built for SEO keyword research.