This question is somewhat related to this question on multiple entries but it's actually quite different (and not a duplicate) which is why I've created a new question.
I'm trying to figure out how a Contact can enter an Interaction more than once. I've come to the conclusion that it's not possible, which is an apparent bug.
Previous Releases: in previous Journey Builder releases, a Contact could not be in the same version of an Interaction simultaneously, but they could re-enter an Interaction, providing they have previously exited the Interaction and met the Contact Filter Criteria (in the Interaction Trigger) on re-entry.
Jan 2015 Release: in this new release, a Contact Entry Mode has been added to the Interaction Canvas in Journey Builder. When set to 'Multiple Entries', a Contact can re-enter an Interaction even if they are already moving through the Interaction.
I cannot get a Contact to re-enter an Interaction in any scenario — even if they've already exited the Interaction.
I'm using the Fire Event in Automation Studio to get the Contact to enter the Interaction.
I'm aware that after the Fire Event Activity runs the first time in an Automation, only new Contact Records are injected on subsequent runs (as documented here, refer to step 4). That's fine, but if I create a new Automation with a new Fire Event Activity (linking to the same Data Extension), it won't work.
It appears that if a Contact has already been injected into an Event by any Fire Event Activity in Automation Studio, then they can't be injected a second time.
This begs the question, how is it technically possible for a Contact to enter an Interaction more than once? Perhaps this can only be achieved using the contactEvents REST method, but I can't get this to work at all — the method always returns an
Internal Server Error as explained here (Salesforce has acknowledged this issue and are investigating).
I would love to understand if there is a solution for this.