The primary difference is that Long Tail Pro is a big time saver over MS. With Long Tail Pro you are able to enter in multiple seed keywords at once (rather than just 1 with MS). So, instead of entering in 1 seed keyword, waiting five minutes, then going back and entering in one more; you can enter 5 seed keywords (for example), hit generate and then see all the keyword ideas at once!
I use Ahrefs to find ideas for keywords to add into content, and content to create around keyword opportunities. I like how Ahrefs shows keyword difficulty, search volume, traffic potential (how much organic search traffic it’s possible to get when you rank #1 for a parent topic keyword) and lets you group keywords together to create lists. It’s really useful.
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.
Keyword Discovery is a paid subscription service that offers marketers the ability to see keyword data across multiple search engines. They maintain one of the largest databases of searches, (nearly 38 billion) which are compiled from over 50 different search engines. The search data shown is a record of the number of times the exact keyword or phrase has been searched over the last 12 months across all 50+ search engines. You would assume that the search volumes would be much larger than any other tool because of Keyword Discovery’s access to data from over 50 search engines, but the fact that the keyword matching option is set to exact, greatly reduces the total volume. Unlike Google’s tools, Keyword Discovery does not collect or show data relating to paid search, such as Suggested Bid, Cost per Click, and Competition. Data is collected daily, but updated monthly. Although you must pay the subscription to have access to all the features, Keyword Discovery does provide a free alternative.
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.