We are a nonprofit. We're interested in starting to use AAD Premium P1 for some advanced Multi-Factor Authentication features, but I don't understand how the pricing works. I have an option to subscribe to Enterprise Mobility + Security E3 for $2.50 per user per month, which is a great deal, and it includes the first 50 users free, which is even better. EM+S includes AAD Premium P1. But how does this work? I have more than 50 users. If I sign up, does it convert my entire tenant to Premium P1, meaning I have to start paying (X minus 50) * $2.50, or can I select specific users to have P1, staying under 50?
I have talked to a couple of sales people who do not know the answer to this question.
Problem is that many Microsoft products don't enforce licensing, meaning that functionalities might be available for all users even if you have a single license in the tenant. You should still make sure that you do have enough licenses purchased, and assign them to all relevant users.