a few months back people were trying to map out their audience and twitter space through this map. it was an interesting exercise to see how cluster of communities can be traced and connected despite such a loose structure.
unlike twitter, mastodon has a server address that kind of grounded you within a community group instead of making it easy for you to dip in and out different zones (fediverse and hashtags are not a default mechanism but an active filtering process).
atm i'm hoping and wanting to see some familiar users from my old network to have a mastodon, but it might be tricky to find them as a username isn't enough to chase them up.