Jeffrey - We have a joint system through Everbridge with the county and one of our adjoining cities. We use the system for things like water service disruptions, missing persons, police alerts about an emergent situation, hazardous materials incidents, etc. We have also used it to announce important citywide initiatives like a recent special census.Some of the features we like are the fact you can pick your preferred optional weather notification settings, including times it won't call (i.e. middle of the night). Also, the ability to register multiple addresses for notifications (i.e. kid's school, parent's house, etc.)You hit on one of the biggest problems which is getting those without landlines (cell only or VOIP) to register their information so they get contacted. Each time we have an incident we try to follow-up with an outreach message along the lines of "Did you get a call about X? If you didn't, it is because you haven't registered ...". The other big problem we have is just getting people to answer the phone from a number they don't recognize. Since we are in a joint system, the caller ID doesn't show our city name, but even if it did, I am not convinced people would answer. If we do a citywide call to 13,000 plus households, our actual answer rate is dismal, and while the people might eventually get the message via voice mail, that kind of defeats the purpose of an "emergency" call. Thus, also getting those people with landlines to register so we also have a cell number or e-mail for text/e-mail messages is important.One other thing we also use it for quite a bit is employee notifications - fire call backs, etc. Several departments have set up internal notification networks. Hope that helps some.