How about you, BC, care to try the four questions?
Ugh, now I have to think
but ok...
1. What does the medium enhance?Connection between people, for anything from keeping in touch to selling things to dating.
2. What does the medium make obsolete?Nothing I can of. Just My Space and Friendster...
3. What does the medium retrieve that had been obsolesced earlier?This is something I've often thought about. In a way it's brought life back to centuries ago in the way we stay connected. For example, it hasn't been a way of life to know what someone you went to high school with is doing these days, but all of a sudden, you can easily friend them and see who they married, what their kids look like etc.
It can make for interesting dynamics too of a bygone era. Say you break up with someone, all my life we said goodbye and parted ways and I thought of them from time to time thinking what they're up to. Now, if I stay friends with them and their family/friends, I know all of it.
Facebook brought that aspect of life from an era long ago when communities were smaller and there was no escaping your lot unless you deliberately made changes to it (equivalent of unfollowing your ex's mom).
4. What does the medium reverse or flip into when pushed to extremes?I'm not sure I understand this question, but pushed to extremes as in the bad parts of it... it would be the social experiments like Cambridge Analytica, also Fake News and Invasion of privacy.