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Start a blog on a subdomain of the main domain. It is hard to do content marketing without a blogging infrastructure. You could easily install WordPress on a subdomain and brand it like the business. If you a curating content for both locations the key is to not duplicate the content exactly. So if your are creating a post as to what ATV is best. Make sure the title and the content are different between each site. The concept can still be the same. Split the testimonials by business location. They are technically 2 different stores anyway. As long as you are not copying word for word you should be fine!

The first thing I would do is focus on answering the questions people have. You can do this by typing in a product category (like motorcycles) at http://answerthepublic.com/. Based on a white paper released by STAT there are several types of questions that populate featured snippets at a faster rate, so I would focus on answering the what, why, and how questions first, and answer those questions in either Sounds like you're going to have some serious CMS limitations but hopefully this helps you add content in a meaningful way to your client's website.