I have a Q/A site that deals with my area of medical practice. I'm a doctor and a programmer. Users can do the typical things like follow threads and other users.
I don't want to spam users all the time with email updates on activities of followed users but I want to keep things 'circulating'. It hasn't launched yet so I face the obvious issues of almost no users to begin with.
What's the best approach - email users in real time when relevant activity occurs or send out periodic emails containing all the latest activity since the last email (I suspect this option will be difficult to program)