Do you know that Google algorithms are so smart today, that merely low/high keyword density doesn’t cut it any longer?
It may sound cliche, but the answer is relevance. Allow me to explain.
Just writing an article around a keyword isn’t enough any longer. No matter how high or low the keyword density. It simply doesn’t work any longer. Hasn’t worked for at least 2 years now. Maybe longer.
You need a string of related key phrases that are well distributed and naturally sprinkled throughout, with variants of themselves right there in your article. Now. You may think that writing an article naturally is going to result in such content. But. More often than not, it doesn’t. Unless you want to rely on chance.
You could use the Google keyword tool to find related or LSI keywords. But that isn’t absolutely mandatory. It is the best way to go though. Alternately, if you just come up with natural phrases based on how you’d search online, that will probably get you ranked for at least some low competition keywords.
Let me give you an example.
Let us say your keyword is “car insurance online”. So you’d need to have it in your opening para, closing para and with an overall kw density of less than 2% but at least 1%. But you need to have related keywords, 10 per 500 words, that are used exactly once or twice each that are relevant to the discussion but not all made of the same key words.
So half of them can be variants of those words like online car insurance or insurance for cars.
While the remaining half could be variants that use different synonyms to mean the same thing. Like protection for motor vehicles and so on.
And if you wish to target a high competition keyword, then it is best to have an authority website that does with low and medium competition keywords from a niche within your niche.