You don’t really need to worry about the volume size either. Too big a number just means you will have to work harder to get ranked in Google. It’s now quite commonplace to see SEO people say it’s best to just go with your gut feeling on a keyword. Just go for something you would type into Google search yourself instead of beating yourself up trying to find that ‘one’ killer keyword.
If you are a locksmith or a pizza shop mobile search ads which drive conversion oriented calls are highly valuable. However for businesses with more complex sales funnels desktop visitors have a substantially higher visitor value than mobile phone users. In August of 2016 TripAdvisor executives stated their visitor values on desktop and tablet devices were similar, but cell phone visitors were only worth 30% to 1/3 as much. Smaller businesses likely see a deeper click value discount on smart phones and other small mobile devices where typing (and thus converting) is hard to do.
Wordtracker is another service that requires an annual subscription to utilize all of its features. Their database is made up of 330 million search terms, collected from the major metacrawlers, Dogpile and Metacrawler, and is updated weekly. The search data they show is a record of the number of times the exact keyword or phrase has been searched in the United States over the last 365 days. As in the case of Keyword Discovery, this difference in default keyword matching type causes Wordtracker to display search volumes significantly lower than what Google’s tools show.

"With Google giving over the home page to ads and their own properties for commercial keywords, the Long Tail keyword is more important than ever. If you have a website, you know that most of your traffic comes from keywords you never would have thought of. With Keyword Researcher, you can find them in advance and make sure that you're the one that snags this traffic. I use it for all of my e-commerce site planning."
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).