A drop in rankings can be difficult to diagnose. Google has 200+ signals and it’s difficult even for an internal employee at Google to find out why.
However, I realized that I had forgotten to include the word “computer repair shop” on many of our pages when we had to re-write and migrate our content to the new CMS.
However, Google has said many times that keyword density is not a big ranking factor as one would think. While many SEO experts think otherwise.
Though, I do remember that John Mueller had also said during Google office hours that you should explicitly mention the keywords that you want to rank for on your page rather than leaving it to Google to guess.
With that in mind, I started optimizing all of our pages to make sure that “computer repair shop” keyword was mentioned clearly for Google to know. Though I don’t have an exact number of how many times we mention it on each page, I made sure that Google knows that the keyword is important to us.
Having done SEO for quite some time, I no longer need to count keyword density. I can write content with keyword density in mind while keeping it sound natural.
Google may tell you not to worry too much about keyword density. But in my opinion, you should pay good attention to it.
Within 3 weeks (maybe only even 2 weeks), our rankings had jumped from 100th to 1st spot for “computer repair shop” and related keywords. Eventually, we settled on the 1st or 2nd spot.
So, my take here is that keyword density still matters in SEO. While sometimes Google might figure out what keywords you should rank for without your page mentioning it, you should not rely on Google to do so.