The keywords you want to focus your SEO on should closely resemble the vocabulary of your audience. In order to come up with the proper keywords you really have to get inside the heads of the people who search for your website. What terms will people use? How do people search? Which question does your website answer? You should create a list of all search terms people could use and think of combinations and nuances within these search terms.
As for the history of the company, as I explained, I created Long Tail Pro back in 2011. At the time, I was creating tons of niche sites and was doing alot of keyword research and content creation. I was trying to figure out what types of keywords would rank quickly in the search engines, specifically Google, and I was frustrated with the other keyword research tools (in particular Market Samurai) out there.
Analyze Keyword Difficulty – Targeting difficult keywords with the highest competition is not always the best idea. The SEMrush Keyword Difficulty tool helps you determine keywords’ difficulties. By indicating a particular keyword’s percentage of difficulty, this tool helps you estimate how easy it would be to seize your competitors’ organic positions in the SERPs.
If you don't know the difference between head terms and long-tail keywords, let me explain. Head terms are keywords phrases that are generally shorter and more generic -- they're typically just one to three words in length, depending on who you talk to. Long-tail keywords, on the other hand, are longer keyword phrases usually containing three or more words.
2) SpyFu: I suggest to have paid account on SpyFu. I just need to find my competitors who using Adwords and review them using this tool. It will show me what ads and keywords they are using. Note that my competitor who paid for that particular keyword knows exactly that it is important for his business including recent trends. Also using SEO feature you can input any URL and find our which keywords they are ranking for.
You can filter your results by 24 business verticals, including Apparel, Arts & Entertainment, Autos & Vehicles, Beauty & Fitness, Books & Literature, Business & Industrial, Computers & Electronics, Finance & Banking, Food & Drink, Toys & Games, Health, Hobbies & Leisure, Home & Garden, Internet & Telecom, Jobs & Education, Law & Government, News Media & Publications, Family & Community, Occasions & Gifts, Pets & Animals, Real Estate, Retail & General Merchandise, Sports & Fitness, and Travel & Tourism.
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).