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Hi. First of all,  I love MOZ and learned a lot about SEO by reading articles here. Thanks for all the knowledge that i received here. I read all the articles about "Subdomain vs Subdirectory"  in the MOZ community and I have no doubt that subdirectories are the best option for a blog. But, the company that I work now has a blog with more than 17.000 articles, 1.000 categories and tags, hosted on a subdomain structure. The website has a Domain Authority of 78 (I am working to improve these numbers)  and the blog subdomain has the same (78). We had 2.7 million hits per month in the blog and 4.5 million hits per month in the site. I am advising the company to change the blog structure to subfolders inside the domain, but I'm finding resistance to the idea, because the amount of work involved in this change is enormous and there is still the fear of losing traffic. My questions are: Is there any risk of losing traffic with the amount of articles we have? What do we probably get if we change the blog structure to subfolders? Could we have increased authority for the domain? More Traffic? How can I explain to my superiors that we would probably have increase traffic for our keywords? Is there any way to prove or test the gains from this change before we run it? Thanks in Advance.