This is slightly more complicated than it used to be, because you have to actually create a live AdWords Campaign as part of the process! This puts many people off, as it looks as if you have to actually advertise in order to use the tool. You don’t — you can just setup the campaign and then pause it before it runs so you don’t have to spend a penny.
Recently I had a dilemma with one of my projects, it is related to ecards and many people still using word “cards” instead of “ecards” but Google Keyword Planner and some other tools showed almost the same information for both keywords. At the same time I did not want to have many words “cards” and “ecards” on the landing pages. Semrush helped very much. I found correct data and made a nice PPC campaign.
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).