2) SEMrush- This tool offers fantastic competitive research around domains to find what keywords could be driving traffic for your competitors. Looking at paid keywords ad spend can also help you know which keywords might have monetary value worth pursuing organically. If a competitor is willing to spend a high ad budget on terms and you think they do a good job running their ad campaign, then its a good indication it is worth organic ranking effort.

Trying to rank for the keyword “Best Headphones” will see your post, page, or article buried in the depths of a billion search engine pages, and it’s never going to surface in the top thousand pages, let alone page one…ever! But going for a keyword, or Long Tail keyword phrase “What are the Best Headphones for Sleeping” will stand you in better shape to get somewhere close, or even on, the first page.
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).