I see some of the big viral sites use a lot of subdomains. ell.viralsite, zack.viralsite. bae.viralsite etc Why exactly do they use sub domains. I see this more when the links are being shared from other pages. Are these for tracking purpose? Also, how are they having the same content on all the sites. Sub domains would mean virtually different sites, so contents are duplicates. So I am not really sure what is happening. Can someone please enlighten. And how about the redirects. I am assuming that is to prevent facebook from think the url is spam, but I am not too sure how a redirect helps. Won't fb be able to detect when a URL is redirectling to the same destination domain. Or does this have a different benefit?