What would be the preferred choice to send a message to multiple Actors, using pub-sub or using an ActorSelector with some kind of wildcard. What does the choice depend on? Pub-sub seems better since the Actor itself is then not concerned with finding those Actors that must be notified, since they tell the Actor they want to receive the messages. On the other hand, selectors allow you to send stuff to an Actor that may or may not exist, which also seems useful. Any "rule of thumb" to see what fits best in a certain case?