Duplicating an audience gives you an independent copy to edit, leaving the original exactly as it was. It is the safe way to make a variation of something that already works, and it is the first step of any A/B test.
Duplicating one
Go to Profiles in the left menu and open Audiences.
Find the audience you want to copy.
Select the duplicate icon to the right of it.
The copy appears in the list, named to show it is a copy.
Open it, rename it, and change the filters you need.
Rename it before you do anything else. Two audiences with almost the same name is how the wrong one ends up on a campaign, and you will not notice until the results look strange.
When to copy rather than edit
The original is live on a campaign. Editing an audience changes who that campaign reaches. Copy instead.
You are running an A/B test. Two audiences from one base is the required setup. See A/B testing with audiences.
You are repeating last year's campaign. Copy the audience and move the dates rather than rebuilding the filter stack from memory.
You want a narrower version of something broad. Copy, then add the extra filter.
What this does not do
The copy is a snapshot of the filters, not a link. Change the original afterwards and the copy does not follow.
It does not copy campaigns. You get the audience only. The campaigns using the original are untouched.
It does not copy the preview. Select Load preview on the new audience to see who is in it.
Editing an audience already on a live campaign takes effect immediately. That is the reason this feature exists.
What to do next
See Audiences for which filters are available and which article describes each one.
Getting help
Open Help at the bottom of the left menu and choose Talk to Us, or email support@bookboost.io.