"reduce the number of receiving actors"

[evanp]

Section 7.1.3 says, in part:

When an object is being delivered to the originating actor's followers, a server MAY reduce the number of receiving actors delivered to by identifying all followers which share the same sharedInbox who would otherwise be individual recipients and instead deliver objects to said sharedInbox. Thus in this scenario, the remote/receiving server participates in determining targeting and performing delivery to specific inboxes.

This doesn't reduce the number of receiving actors -- it reduces the number of HTTP requests, while still delivering to all actors.