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 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.
Be sure to re-evaluate these keywords every few months -- once a quarter is a good benchmark, but some businesses like to do it even more often than that. As you gain even more authority in the SERPs, you'll find that you can add more and more keywords to your lists to tackle as you work on maintaining your current presence, and then growing in new areas on top of that.
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).