I think I'm starting to really get Mastodon after looking at m.sprovoost.nl and himk.am vs bitcoinhackers.org. Each instance doesn't need 1000s or millions of users to be succesful (aka network affects). It can be as small as hosting a couple friends and strangers. The data resides there but can interact with virtually any unblocked federation instance.
@Clashicly there is an optimum amount for each instance. But at the moment there are just learning pains. Like migrating follows. I bounce back and forth of three instances.
Bitcoin Maston Instance