I actually don't use any keyword tools aside from Google Trends, but only rarely do I even use that. I try to talk to many of our target audience members (entrepreneurs) as I can. I attend events, I have phone calls, I sit next to them while working. Generally speaking, I think it's a waste of time to START with keyword tools instead of actual customers. Yes, you can target people in broad swaths and get a high level sense for what's interesting and trending, but at least in the case of our business at NextView Ventures, it's way more powerful to talk to actual "customers" you serve.
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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

I’ve owned a dozen or so Keyword Tools in my time and most of them are basically the same, but I’ve always thought the best Long Tail Keyword research tool is the very quiet and reserved Keyword Researcher Pro. I don’t see it being shouted from the rooftops and I don’t see any aggressive marketing for it, but my…it’s a real useful tool that I now wouldn’t be without.
However, KWFinder has a couple of areas where Longtail Pro outshines it. Firstly, I like the fact LTP provides you with a suggested keyword competitiveness to target (as described above). More significantly, I don’t like the way that KWFinder restricts your number of keyword suggestions if you choose their cheaper pricing tier – it feels like they’re holding back some of the power of the software unless you pay more. With LongTailPro, you can see as many keyword suggestions you like so long as you’re within your monthly allowance.
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.