With reference to the below question, I'm interested to know why it was closed.
The question seems to me to be asking how to use ASP.NET MVC to serve content in response to an http request that differs depending on context (in this case the host name). Is that really off-topic for stackoverflow?
As a comparison, if this question is off-topic, wouldn't asking how to serve different language content based on the domain also be off-topic, as in:
We should at least be consistent?
(With (a lot of) respect to the (very high rep) mods users that closed it, none of them have any .NET languages or ASP.NET MVC in their top ten tags, maybe they misunderstood that this is exactly the kind of problem that the ASP.NET pipeline is there to solve?)