So what exactly is Keyword Competitiveness (KC)? It’s only the feature within Long Tail Pro that completely changed the game and made keyword research so ridiculously simple that even a dumb truck driver like me could become an expert! It basically works like this. As soon as you click the button in Long Tail Pro Cloud to retrieve keywords, it automatically calculates a number for each keyword (between 1 and 100) based on several different SEO factors. Lower numbers mean the keyword is easier to rank for and higher means it is harder to rank for. More on that below…
Google's AdWords Keyword Planner tool is another common starting point for SEO keyword research. It not only suggests keywords and provides estimated search volume, but also predicts the cost of running paid campaigns for these terms. To determine volume for a particular keyword, be sure to set the Match Type to [Exact] and look under Local Monthly Searches. Remember that these represent total searches. Depending on your ranking and click-through rate, the actual number of visitors you achieve for these keywords will usually be much lower.
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.