What would be the advantages and disadvantages of using subdomains of a single domain as separate "websites" for related topics. Eg. Under www.hobbies.com, I could create www.papermache.hobbies.com, www.knitting.hobbies.com, etc
I am one of those that has seen a difference between subdomains and just another file in a folder. I tried both for the same site and noticed that the folder was ranking better than the subdomains. It seemed as if Engines were treating it as a whole other site while the folder was just part of the site with the same PR and links.
One good thing about subdomains is that places like alexa treats all the sites the same when figuring page rank. One bad thing is that if one of the sites gets banned from the google index, the whole domain gets banned. Bill Bakker