+7 votes

Optimizing. That is what is all about. How to optimize good looking adset without risk of loosing a line and end up in learning phase again?

There are a lot of articles about this problem and many of them is saying quite oposite things than others. Even a Facebook shares some leads which can help me/us clarify the problem but without any exact numbers or limits.

Which changes lead us to reenter a learning phase

  • Any change to targeting

  • Any change to ad creative

  • Any change to optimization event

  • Adding a new ad to your ad set

  • Pausing your ad set for 7 days or longer

All of that is clear.

What interests me are the following changes that "may or may not" lead us to reenter learning phase (depends on the magnitude of the change)

  • Ad set spending limit amount: What is the biggest amount or % of current amount I can change to not reenter to learning phase?

  • Bid control, cost control or minROAS control amount: What is the biggest amount or % of current amount I can change to not reenter to learning phase?

  • Budget amount (unless you're using the target cost bid strategy, in which case budget changes aren't considered significant edits): What is the biggest amount or % of current amount I can change to not reenter to learning phase

My additional questions:

  • Changes of targeting which influence potential reach (for example Country, Age, Sex, ...): What is the biggest amount of potential reach or % of current amount I can change to not reenter to learning phase?

  • Will change of placements reenter an adset to the learning phase?: Is some specific placement whose change leads an adset to reenter to learning phase or it depends on the budget spend on specific placement?

If you have any additional conditions or experiences related to this question I did not mention, feel free to share.

by (320 points)
edited by

3 Answers

+1 vote

The standard answer is that everything you listed will restart the Learning process: anything that impacts delivery or targeting will have an impact on performance and thus require FB to re-establish its algorithm coefficients for the campaign.

I generally try to avoid making any changes during the learning period except to simply kill a campaign that's obviously not working. The problem here is that you can only really test one approach / strategy at a time if you're targeting a specific audience, as you wouldn't want to spin up multiple campaigns with different parameters aimed at the same narrow audience. That said, you only need 50 conversions to establish the campaign coefficients, so it shouldn't take too long to exit the learning phase for any given campaign.

So to specifically answer the question, what I understand to be changes that will cause a campaign to restart its learning phase:

  • Changing the bid strategy (target cost, bid cap, cost cap, lowest cost, for VO: min-ROAS or maximum value);
  • Changing the bid strategy cost parameter (eg. bid cap amount);
  • Changing any targeting parameters (eg. geo, phone OS, etc.);
  • Changing any audience parameters (eg. changing the Custom Audience);
  • Changing the campaign budget (for CBO campaigns) or ad set budget;
  • Changing the AEO event;
  • Adding / Removing a creative;

Of the settings you listed that may cause the campaign to re-enter the learning phase, what I've heard is that a change of more than 10% will reset the campaign's coefficients and cause it to start exploring again even if it doesn't explicitly re-enter the "learning phase."

by (14.6k points)
One note: Facebook isn't very transparent about this, so this answer is very speculative. I'd love to be proved wrong on any of these points!
+1 vote
Based on my experience up to 20% change in budget amount / ad set spend limit will not reset your learning, usually I wait 7 days between changes but only so I can measure performance after the change
Expert in User Acquisition by (160 points)
+1 vote
The answer below is the one that I have recently received from FB reps (after switching to CBO) about whether adding a new creative to an existing ad-set resets the learning phase of the ad-set or not:

"Although the learning phase may be triggered at the ad set level in the UI, the “real” learning phase will take place at the ad level. If you add a new ad to an ad set, it does not hurt our system's ability to predict the performance of the existing ads and historical learnings will be maintained.
With this in mind and with a view to not adding extra complexity to the account structure I would recommend adding new creatives within the existing evergreen campaign. Just try to limit the number of new creatives you add to an ad set at a given time so that if they perform poorly they won’t cause large fluctuations in overall performance. Generally, we would recommend having no more than 6 ads per ad set"
Expert in User Acquisition by (170 points)