@oblomov yeah, there's the old "it's like email but for websites!" which isn't terribly inaccurate, but that's honestly more a consequence of "HTTP POST to ldp:inbox" than anything else in AP. the side effects for each activity kinda stray from that model and go into almost RPC-like territory. there's also some potential redundancy with HTTP verbs, but that's because HTTP verbs don't notify arbitrary audiences (although i guess they could do that with a header!)