Im looking at writing a application for a web 2.0 start up site which will essential monitor specific RSS feeds.
Due to the expected up take of such a service I am expecting that taking advantage of cloud computing would be the way to do it, however with my lack of experience I do not know if it is possible to run a Windows service in the cloud.
There will be a web front end to this but it isn't imagined that that will have a heavy load as it will be just for sign up, then users will recevie notifications by SMS/Email
You can run a "service" in the cloud, when using Azure. It's called a "Worker Role" see the Architecture here.