Develop more capabilities to be able to connect with your end users and track who is using your REST services/items. The dependency api that is currently out there kinda works, but I want something deeper where if someone includes a REST service in their applications, the referer gets passed on and tracked. Additionally develop a system where users can "subscribe" to service items in ArcGIS Online or ArcGIS Portal and receive updates.
The end goal is to make REST services & applications more mature by being able to communicate with the users and notify them of outages or changes before they are made, preventing unhappy customers with broken apps.