The purpose of creating sustained messages is to provide totally loosely coupled architecture. In the case of sustained messages the UI components can be loaded asynchronously in any arbitrary order. As soon as a component that subscribes to a subject is loaded (first after a sustained message with the same subject is published) the event dispatcher will publish again the same message to the subscriber. Consider that this is a 1 to 1 publishing so that an already existing subscriber dose not receives same message multiple times. However, this pub sub mechanism differs from GI pub sub only in the persisting the messages. It is the responsibility of developer to unsubscribe an object or function from an event published by this object if it is not needed any more. Subscribing an object or function to a type of event multiple times causes that the function is executes multiple times if a message is published.