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.
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.
It would be great if you can provide comparative analysis of this tool with Google Keyword Planner. Since you’re using this tool so you can provide best comparison. One differentiation which I understood is that this tool works for yahoo and bing as well whereas Google keyword planner works only for Google but Google being a dominating search engine, gives the highest returns, so only this reason may not be enough to buy it.