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I'm trying to improve the SEO for an e-commerce store that I'm working for that sells custom car air fresheners where you select the shape of the item and then upload the photo. The site has been around for almost 10 years so has authority in the field and ranks number one for custom car air fresheners and other related high-traffic keywords. However, there is no blog, no social media and has 8 total pages: landing page, FAQ, contact, guidelines, shape/product (page that starts the ordering process with little text), scents, terms, and samples.
I'm struggling with how we rank higher for specific keywords that we are not number 1 with ok traffic (such as dog air freshener, custom air freshener for car with picture, custom photo car air freshener) and not affect the current keywords that we are ranking number one for. In addition, how do we rank higher for other keywords, if we don't have that many pages like a blog to create content? I was thinking of creating a blog to target more keywords, but I don't think there is enough relevant content to make. And I feel Google would find a blog about "top gifts for dad" or "top gifts for the holidays" not relevant. I was also thinking of adding more text to the shapes/product page which could be tailored towards a keyword. Maybe I could create another product page that goes into more detail about the air freshener with images, descriptions, and other use cases. On MOZ, the Domain Authority is 18 (really low), so I am thinking about working on getting backlinks from relevant sources with authority to improve our SEO. Or do we not mess with the text on the website since it works and not worry about the other keywords and focus on technical SEO items and backlinks to help with SEO? TLDR: How do you improve SEO for new keywords for an e-commerce business that doesn't have a lot of pages for content without affecting its number 1 ranking on other keywords?