@silverpillThe Activity Vocabulary defines Follow on an object, while AP describes delivery and assumes an actor. Both are true at their level. My idea is not to make the Note an actor, but to let the author's actor handle the Follow for its own thread, since it already has an inbox and a key. Your observer creates a new actor per object. Mine reuses the one that already exists. Both need support on each side for real time. Polling is just my fallback when a server does not.
