I wish to make a website where customers who register can get a subdomain on my small primary domain a la blogspot.com (ex. user.mywebsite.com)

I truly don't understand how to get about carrying this out. I suppose this can involve DNS. Here's more information on my requirement.

  1. Don't have to setup an IIS website either.
  2. I would like an application that will route the subdomain to some folder within the directory.

Would this be achieved utilizing an ISAPI DLL? some DNS miracle? What?

All clues is going to be welcome and useful.

Thanks

You most likely want to check out wildcard DNS after which check if the website really is available inside your application. Setting each one of these up in IIS could be a little untidy.

http://en.wikipedia.org/wiki/Wildcard_DNS_record

Maybe it will help? It comes down to settingg up a wildcard for sub domain names. After that you can look into the Uri.Host property to determine which subdomain was requested.