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My client has 24 separate subdomains for its nationwide business, one for each specific location. Much of the content is very similar, as the site serves  as a lead-generator for rental reservations. After years of suggesting the approach of using one domain, we have finally gotten the client onboard to eliminating the subdomains and maintaining a subdirectory/page approach for location-specific content and allowing universal content to live at the root domain. I've been looking for any case studies that have any watch-outs or demonstrated benefits when collapsing domestic subdomains (phoenix.client.com; albuquerque.client.com, etc.) into the root, and have been fairly unsuccessful so far. We will be setting up a rigorous 301 redirect tree to ensure we retain as much link juice as possible from any existing subdomain-specific inbound links. Any advice/guidance to help set expectations of what will shake down from this change? It feels like we should see increased domain authority and less cannibalization, as the client ranks nationally for important broad-level keywords, with significantly higher DA at the root level than any tracked competitors, but I'm a little nervous about how localized search results will be affected. Thank you!