Because someone who is looking for something that specific is probably a much more qualified searcher for your product or service (presuming you're in the blogging space) than someone looking for something really generic. And because long-tail keywords tend to be more specific, it's usually easier to tell what people who search for those keywords are really looking for. Someone searching for the head term "blogging," on the other hand, could be searching it for a whole host of reasons unrelated to your business.
The link back to googles API is crap – it keeps coming up with password authentication which renders it virtually useless when trying to find your own rank. Sells you the software initially. But then tries to sell you a load of stuff afterwards which effectively tells you the first version you have already paid for is useless without the extra “bonuses”. Not a nice way of doing business
"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."
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.