I also want to emphasize that Microsoft Excel and Google Docs perhaps play an equal, if not more important role in keyword research than any of these tools, because at the end of the day, the mountain of data you end up with is of no use if you can’t perform calculations, sort, filter, present or store it in a way that’s best suits the task at hand. Head over to Distilled for a comprehensive Excel for SEOs guide. Alternatively, bug this guy—he’s the Sensei who trains Excel ninjas in the dark of the night.
It arranges your search volume by separating the relevant keywords from those considered irrelevant. It presents those keywords, which it believes would help rank your search engine very high. Once you indicate that you want your keywords to be filtered, the tool would help to arrange that. You know that is very important for your Adsense and adwords campaign. The program is relevant for your CPC and other internet marketing strategies that you want to use.
Jaaxy uses a combination of search engine data from the major search engines (Google, Bing and Yahoo) and Long Tail Pro get its search data from Google alone (via the Google Keyword Planner tool). While this seems to be an advantage for Jaaxy, you might only be interested in getting information from the number one search engine in the World: Google.
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.

This comes with a monthly fee though, so why have that recurring revenue drain when you can just get MS or LTP for that matter on a one off fee. They are both virtually the same in my opinion. This is the only thing that is stopping me from buying the software. If the calculation of keyword difficulty was included in the one off fee, i wouldn’t mind paying the full $97.
Customize the data that LTP is going to fetch with pre-filters like “Suggested Bid” (or Cost per Click [CPC], i.e. the amount of money an advertiser is willing to pay for a click on their AdWords ad that is targeting that specific keyword), “Local Search Volume” (average number of monthly searches for a specific keyword), “Advertiser Competition” (the amount of advertisers competing for a specific keyword) and “Number (of) Words” (very important when you’re trying to find long-tail keywords).
I’ve found google trends to be an interesting way to see if a keyword (and by extension a niche) is growing or shrinking, and whether it’s seasonal or not. I can’t think of any other tool out there that can reliably tell you this information, so that’s really useful. Also, if you’re building a site, especially an authority site, getting onto something that’s trending upwards is a fantastic idea.

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).