I,too,first came across the writings of Magister Rose soon after discovering and exploring the "inter-webs".
Granted, I'd been aware of the Church of Satan
for some time at that point. I just didn't have a clue that it had grown into a world-wide membership and wasn't still simply limited to 1960-70's San Francisco.
Man, was I wrong!
How could I NOT join after having read The Satanic Bible, The Satanic Rituals and The Satanic Witch to tatters and finding out that The Church of Satan
was alive, well and thriving!?
I have interacted online and in person with several amazing fellow CoS members over the years.
What have I gotten out of it?
Iron sharpens iron.