I have been doing tons of keyword research, and I have tested the difficulty with many many softwares: Ultimate Niche Finder Market Samurai Traffic Travis Stealth Keyword Analyzer SpyFu And my conclusion after looking through 100,000 keywords.... There is no correlation to determine the easiest keywords to rank for using software. Ok, I'll go a little into this. The difficulty is very broad, there is a correlation bewteen "payday loans" and "buy purple donkeys with fluffy ears", but when you delve deeper, often they have complete opposing difficulty levels. SpyFu explained how they get their difficulty very thoroughly which leads me to believe they know it best. I would have to agree slightly, that when looking at the top 20 results, they do get closest most often when compared to other software, but still get it wrong a lot of the time. I would have to say, the softwares that give a difficulty rating are the most wrong. My conclusion is that if you want to find keywords that have low difficulty, and high searches + value, DO IT MANUALLY. Only use softwares as an AID, not a conclusion.. Just wanted to clear this up, and I hope this helps someone when doing keyword research.