About the learning phase

Each time an ad is shown, our ads delivery system learns more about the best people and places to show the ad. The more an ad is shown, the better the delivery system becomes at optimising the ad's performance.

The learning phase is the period when the delivery system still has a lot to learn about an ad set. During the learning phase, the delivery system is exploring the best way to deliver your ad set – so performance is less stable and cost per result is usually worse. The learning phase occurs when you create a new ad or ad set or make a significant edit to an existing one.

The Delivery column reads "Learning" when an ad set is in the learning phase. While the delivery system never stops learning about the best way to deliver an ad set, ad sets exit the learning phase as soon as performance has stabilised usually after around 50 optimisation events since its last significant edit.

During the learning phase, ad sets are less stable and usually have a higher CPA. To avoid behaviours that prevent ad sets from exiting the learning phase, we recommend that you:

• Wait to edit your ad set until its out of the learning phase. During the learning phase, performance is less stable, so your results aren't always indicative of future performance. By editing an ad, ad set or campaign during the learning phase, you reset learning and delay our delivery system's ability to optimise.
• Avoid unnecessary edits that cause ad sets to re-enter the learning phase. Edits that meaningfully change how your ad set might perform in the future can cause an ad set to re-enter the learning phase. Only edit your ads or ad set when you have reason to believe that doing so should improve performance.
• Avoid high ad volumes. When you create many ads and ad sets, the delivery system learns less about each ad and ad set than when you create fewer ads and ad sets. By combining similar ad sets, you also combine learnings.
• Use realistic budgets. If you set a very small or inflated budget, the delivery system has an inaccurate indicator of the people for whom the delivery system should optimise. Set a budget large enough to get at least 50 total optimisation events and avoid frequent budget changes (which can cause an ad set to re-enter the learning phase).

The learning phase is necessary to help the delivery system best optimise ads, so you shouldn't try to avoid the learning phase completely. Testing new creative and marketing strategies is essential for improving your performance over time.

If your ad set isn't getting enough optimisation events to exit the learning phase, the Delivery column status reads "Learning limited". Learn more about ways to fix learning limited ad sets to improve your performance.