What everyone forgets is how important 'notifications' on Facebook are. When making a post, many if not most residents are likely to see the update. It may even be better than physical mailers, and I doubt many other options even compare for awareness.
A website is unlikely to get nearly any traffic, and especially not timely views for upcoming events. Emails will probably head to spam or not get read.
It shouldn't be Facebook as the default, but the simplicity of reaching most of your audience is valuable.
How would you even measure that? Announcments don't really require engagement or acknowledgement. I guess you could A/B test announcing city hall events and watching for turnout?
A website is unlikely to get nearly any traffic, and especially not timely views for upcoming events. Emails will probably head to spam or not get read.
It shouldn't be Facebook as the default, but the simplicity of reaching most of your audience is valuable.