You cannot have a guarantee that you will enhance your ranking and get to the top ten results by making use of the most popular keywords. The situation may worsen when you keep on increasing the amount of content on your website. The only way you can be sure of recording success in your campaigns is by making use of keywords that are not only creative but also relevant. This is the main reason why we have the AdWords and SEO keyword permutation generator tool. The interface of this tool is very easy to use and has three boxes for text entry and you will be required to fill in as many keywords and you like and the generator will work out several permutations that produce very creative and useful keywords that you can include in your content. However, you will be expected to keenly watch the keyword generator because some of them may not make sense.
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.
So whilst Long Tail Pro has just continued to grow in revenue every single year and comes highly recommended, you may want to check if all the important features are fully functioning before signing up. Especially the KC feature (keyword competitiveness) as it is so fundamental to keyword research and making an informed choice on whether or not to go into a particular niche.

The limit on manual keywords could be higher.  I personally wish we could input 10,000 keywords at a time, instead of 200.  However, I understand the costs that Long Tail Pro has to maintain each time a new manual keyword is input.  Not a deal breaker, I just wish the limit was higher. (To be fair, I don't think most keyword tools have a bulk manual option at all).