I recently came across and article that hits the nail in the head when it comes to communication strategies to large audiences that can contain many different segments. Here is a good snippet of the main message:
"The more specific your segmentation and targeting, the better you enable yourself to write. Writing a message to “all users” means you have to introduce your product, remind everyone what it is, what it does, why you’re writing to them, etc. All of this adds dead weight to the message for your active users who know it all. Do this enough times and they’ll just stop reading what you write. You’re teaching them to ignore you. Stop it."
Read the full article here.