A new client has mainsite.com and a large numer of city specific sub domains i.e. albany.mainsite.com. I think that these subdomains would actually work better as subfolders i.e mainsite.com/albany rather than albany.mainsite.com. The majority of links on the subdomains link to the main site anyway i.e. mainsite.com/contactus rather than albany.mainsite.com/contactus. Having mostly main domain links on a subdomain doesnt seem like clever link architecture to me and maybe even spammy. Im not overly familiar with redirecting subdomains to subfolders. If we go the route of 301'ing subdomains to subfolders any advice/warnings?