Some customers convert immediately, others – need more time. Thus conversions can happen even when an ad set is already on pause. Such late conversions can turn your once inefficient ad sets into profitable ones. 

Let's set up a rule that will unpause ad sets if their CPA goes below your maximum value. Such rules are also called the 'safety net'.

Navigate to the Bïrch Rules page and click + Create rule

Select your ad account and under Filter select ad sets that the rule will start.
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If you want the scope of the rule to exclude ad sets that have not been active for a long time, you can add a filter based on the metric to make sure such ad sets are not activated. For example, Ad set metrics Impressions in the Last 30 days > 0

This way, the rule will not match ad sets if the collective count of impressions over the last 30 days is 0.

The first condition checks the CPA value. Set your desired value here.

The second checks whether there were purchases. If there weren't, the CPA will be equal to zero, which is always less than any value that you enter. You don't need to edit this condition.

Here is what you get as a result:

Alright, the rule is ready. Let's go live!
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