This keyword tool was built on a custom database we have compiled over the past four years. We researched data from the (now defunct) Google Search-Based Keyword Tool and also looked at a few more recent data snapshots to refresh the database and enhance our keyword coverage. Our database contains 28,527,279 keywords representing 13,762,942,253 monthly searches. Our database is primarily composed of English language keywords.
The Google Keyword Planner used to be great it's now frustrating to use.... and almost impossible to get in to without setting up your first ad. Big shame google big shame. I would love to share more info about your tool over on my website [link removed by moderator] for my local business clients - have you got something you can send over for me to add to the site?
In a nutshell, Long Tail Pro helps you quickly find keywords in bulk based on a seed keyword that you input. In addition to returning hundreds of related keywords, the tool also shows search volume (monthly search volume), advertiser bid, number of words, rank value, and my favorite Keyword Competitiveness (helps you judge the competition and keyword difficulty).