If you want to pause/start/change the budget of your TikTok ad groups or campaigns based on their dynamic performance, you can use metric comparison in Bïrch rules!

Let explore one example: setting the rule to automatically increase the budget if CPA today is 30% lower than yesterday.

We are going to set the rule at the ad group level, so that it checks only active ad groups:

Feel free to apply other name or status based filters if you want to target specific ad groups.

Since our ad groups are optimised for purchases, we will be comparing how Cost per Purchase yesterday compares against today's results. So the rule will give an ad group a 10% budget boost if the Cost per Purchases today is at least 30% lower than yesterday:

Besides, we want to set a threshold for number of conversions today to check the statistical significance:

You can use any other CPA that suits your business type. Here is what the general formula would look like:

CPA Today < 0.7 * CPA Yesterday

AND

Conversions Today > 10

So if both conditions are met, the rule will increase the budget of the ad group.

You can set the rule to check either by a custom schedule or use standard frequency like every 60 minutes:

This smart automation ensures that we're putting more spend behind our most efficient campaigns, scaling results without any manual work. Feel free to customize the timeframes and percentages, and let us know if you have any questions!