These three filters segment guests by what they did with your previous campaigns: opened, clicked, or simply received. Their most valuable use is not targeting the engaged, it is suppressing the recently contacted, so you stop sending the same people four messages in a week.
Every filter has an Exclude selected option that inverts it, and filters combine with AND. See Audiences.
Opened campaigns
Guests who opened a specific campaign email. Select one or more campaigns from the list.
All time toggle. Turn it off to limit the filter to a window, such as the last 30 days.
Exclude selected. Removes those guests instead, which is how you follow up with the people who did not open.
An open is weak evidence of interest. Treat it as "this address is alive and the subject line was not offensive" rather than as enthusiasm.
Opened and clicked campaigns
Guests who opened and clicked a link inside the campaign. Same settings as above.
This is the one that means something. A click is a deliberate act, so this group is worth a different message from everyone else.
Received previous campaigns
Guests who were sent a specific campaign, whether or not they engaged with it.
Within X days. Limits the filter to a recent window.
Exclude selected. Removes anyone who already got it.
Exclude plus a day window is the frequency cap. Set it to exclude anyone who received a campaign in the last seven days and you have a rule that quietly protects your list from over-messaging, without anyone having to remember who was sent what. Bookboost does not apply a cap for you, so this filter is the cap.
What this does not do
Open tracking is unreliable by nature. Privacy features in Apple Mail and elsewhere can record an open that never happened, or hide one that did. Build important decisions on clicks.
These filters only see Bookboost campaigns. A guest who engaged with something you sent from another tool looks inactive here.
There is no automatic frequency cap. Nothing stops a guest receiving several campaigns in a day unless you exclude them yourself.
Received is not delivered. A guest counted as receiving a campaign may still have had it bounce or be filtered as spam.
What to do next
To split an engaged group in half and test two messages against it, see A/B testing with audiences.
Getting help
Open Help at the bottom of the left menu and choose Talk to Us, or email support@bookboost.io.