Here is what I can think of off the top of my head at the moment:
E911 emergency response
Law Enforcement
Delivery Services (USPS)
Disaster Response (This is where the library was)
Transportation services (both public & private)
Taxation & Appraisal (The tax rate is too high over there)
Elections (Where do I vote?)
Waste Disposal services (why didn't they pick up my trash)
Insurance Rates (I'm how far from a fire hydrant!)
Location analysis (using address type and density)
Economic Development
It's similar to asking why place is important, so the short answer is that it's important to everything. As I think about some of the topics I have listed I realize it depends on the attribute data too. Perhaps there is no address type field to show residential, commercial, industrial, etc., in which case the data may be less useful...