Whenever any web portal provide hosted service, at that time publishing it through sub domain is the most convenient and preferable way. There are many such free hosted services are available on the internet. For e.g. blogger.com and wordpress.com for blog services. If you have noticed, in such portal, whenever user register for a service at that time it ask for a preferable sub domain, and upon choosing sub domain, service start instantly without waiting for DNS propagation compared to normal sub domain creation scenario.
Few days back one of my friend asked me how to achieve same with ASP.NET. So here we will see how we can achieve same with ASP.NET, IIS, and DNS tweaks. However this post is less about ASP.NET and more about IIS and DNS configuration except IIS Metabase entry automation through ASP.NET. Whole tutorial is divided in three parts: IIS setup, DNS Setup, and IIS Automation through ASP.NET