If someone happens across a micro.blog timeline post, ever more likely with @sod’s excellent Conversation on Micro.blog plugin to facilitate more replies, this is the view they see:
I wonder if it would better serve the visitor (and Micro.blog!) if the standard Reply button was on each post. Right now there’s no indication that they even could join the conversation if they wanted to. If they weren’t signed in, that button could lead them to an explainer that a free account lets them reply, or paid one to write their own blog posts.