I am new and signed up using kbin cafe but seem to be able to post in kbin social. I am guessing each website is like its own email service from what I can see. Though I am not sure if the owner of kbin social is the same as the owner of kbin cafe. I take it anyone can set up their own kbin site and connect it to the other kbin sites?
Omg I just asked the same question!
(Edit) My bad I just realized it was my post.
Just wanted to let you know that this is the best thing I’ve read on the fediverse, and by a fair margin at that.