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Hello, I would like to know if the selection of individual keywords(that are not primary, secondary or tertiary) are important for SEO regardless of the relevancy to the page topic. I am wondering how much of a contribution a non-P1/P2/P3 can make in terms of SEO? For example it is a product page and I have built my content with P1,P2&P3 based only on the product and its properties itself. Do you think that a content gap for the page could be the production process of that product? So even if it is a product and its properties page, I can add 2 sentences about the production, so that I can drive more traffic by including these 2 informative sentences.? EXAMPLE:
So lets' say my topic is "hair types" (P1) and my subtopics are "Straight," "wavy," and "curly"(P2s) which I used as subtitles. But throughout the page, I am planning to add some relevant but not-directly-relevant keywords here and there since they have high metrics and volumes. For example a potential sentence I can add: "innovative hair products these days can offer amazing results for the desired hair types". It is not specifically about "hair types" but I am using the keyword "innovative hair products" (good metrics keyword) which may help for the traffic... Another potential not-so-direct sentence can be: "For all hair types, the hair damages are common: heat damage, chemical damage and mechanical damage". Would adding this extra sentence where I am not specifically talking about "hair types" (my topic) but "hair damages" and damage examples (off-topic high metric keywords) help me to drive traffic to my website? And how much of an impact would it be?