App events enable you to create app activity Custom Audiences and lookalike audiences. This can help you reach people who are more likely to take actions you care about after seeing your Meta ad.

Setting up app events enables you to use campaign optimization types such as app event optimization and maximize value of conversions. These types of campaign optimization can help you find people who are more likely to take valuable downstream actions such as purchasing an item, or help you achieve more efficient return on ad spend.

After you set up app events, you can see your unattributed and attributed events in Meta Events Manager. You can also see how many in-app actions are happening as a result of your ads in Meta Ads Manager, and use other measurement tools such as conversion lift.