It did take me awhile to understand the core concepts of micro.blog. The description on the iOS App Store is illuminating:
And so everyone who follows me on Micro.blog sees my blog posts, and I see theirs. Simple.
And anyone who wants to could just read my blog in an RSS reader instead. All good, all open.
Micro.blog is simply a layer on top of existing RSS/JSON feeds; its simplicity echoes the simplicity of podcasting.