Localservicemap and serviceReaderUrls

[Jonathon -- Improov]

It appears it is possible to have private services defined within a webapp. Is that how parameter 
"serviceReaderUrls" (in web.xml) works?

Does it make sense to have little private services defined within a webapp, never to be reused by 
other webapps?

If the answer is no, then does it make sense to even have a separate dispatcher (WebAppDispatcher) 
for each webapp? Seems like all services in OFBiz are global, not private.

And by the way, why does ContextFilter not automatically create a WebAppDispatcher when no 
"localDispatcherName" parameter is defined? It does so for a GenericDelegator.

Jonathon