You’ve likely felt the impact of Apple’s iOS 14 privacy updates, especially the AppTrackingTransparency (ATT) framework, which fundamentally reshaped digital advertising by limiting access to the Identifier for Advertisers (IDFA). This shift led to a substantial loss of conversion signals, making it harder to measure campaign performance, target audiences effectively, and optimize ad spend.
To address this, Facebook introduced Aggregated Event Measurement (AEM), a solution designed to restore essential performance insights while respecting user privacy. Facebook AEM enables advertisers to continue tracking key conversion events, even when users opt out of tracking, helping preserve campaign effectiveness in a privacy-first landscape.
In this blog, we explore how Facebook AEM emerged in response to Apple’s iOS 14 privacy updates and walk through its key features, setup process, and best practices. You'll learn how to configure AEM for optimal user acquisition performance, compare it with SKAdNetwork, and avoid common pitfalls to ensure accurate and privacy-compliant measurement.
Why Facebook AEM Was Introduced?
Facebook AEM was introduced as a direct response to Apple’s AppTrackingTransparency (ATT) framework, which mandated user consent for accessing the Identifier for Advertisers (IDFA) on iOS 14.5+ devices. This change, further refined to require explicit third-party recipient disclosure, led to high user opt-out rates and a significant loss of crucial conversion signals for advertisers on Meta platforms.
Without Facebook AEM, your campaigns faced underreported conversions and impaired optimization. By prioritizing up to eight key events and aggregating data from opted-out users, Facebook AEM helps restore vital performance signals, enabling you to continue optimizing ad delivery and measuring the effectiveness of your UA efforts in a privacy-compliant manner.
With its purpose defined, here’s how Facebook AEM captures your key conversions.
How Facebook AEM Works
Here's how Facebook AEM works from your user acquisition (UA) perspective:
1.Event prioritization
When you set up Facebook AEM, you choose up to eight conversion events for your verified domain. During each user session, Meta only reports the single event with the highest priority among those you’ve configured. To make this count for your UA goals, rank your most valuable actions, like App Install (Download), Achieved Level, or Completed Tutorial, at the top of your list. That way, if a user completes multiple actions in one session, the one you care about most is the one you’ll see in your reports.
Actionable tips:
You should prioritize your events for campaign optimization by starting with bottom-of-funnel events like "Download." Next, include mid-funnel events like "Download," and finally, list upper-funnel events like "View Content." It's essential to avoid frequent reshuffles of this priority list, as each change initiates a 72-hour cool-down period during which your campaigns will not be able to learn and optimize fully.
2. Domain limits
Facebook AEM caps you at eight conversion events per verified domain. If you’re tracking more than eight actions today, audit your list and narrow it to those that drive real revenue or high-quality leads. Verify your domain first in Meta Business Settings, then configure your events in Events Manager to ensure they all count when iOS users opt out of tracking.
Actionable tips:
Verify your domain before adding events, as unverified domains are not eligible to use Facebook AEM. Additionally, group similar custom events under a single standard event to keep your event count within the allowed limit when possible.
3. Data flow
You add the Meta Pixel to your web pages and send corresponding server-side signals through the Conversions API, ensuring data is captured even when browsers block cookies or scripts. For mobile apps, you integrate the latest Meta SDK and enable Aggregated Event Measurement (AEM) to track real-time in-app events. Configure SKAdNetwork only in your iOS app’s Info.plist; no Android manifest entry is required.
Actionable tips:
Add the Meta Pixel to your website header and set up the Conversions API either through your server or a partner integration. Use Meta’s Event Manager diagnostics to test both implementations. Install the latest Meta SDK for mobile apps and configure the event schema accordingly. Ensure that SKAdNetwork mapping is enabled in your app’s Info.plist or Android manifest, and verify that your SKAdNetwork postbacks align with the events prioritized in AEM.
By following these steps, you ensure Facebook AEM captures your highest-value conversions, respects user privacy on iOS, and feeds clean data into your UA campaigns. Next, follow these exact steps to configure AEM in Meta Events Manager.
Step-by-Step Setup of Facebook AEM in Meta Events Manager (Web)
To help you accurately track and optimize your user acquisition events in Meta’s privacy-driven environment:
1. Verify your domain in Meta Business Settings
You start by verifying your website domain under Meta Business Settings. This step requires Facebook AEM to recognize and report your web-based conversion events.
2. Open Events Manager and select your Pixel
In Ads Manager, go to Events Manager, choose the Pixel you’ve installed on your site, then click Aggregated Event Measurement and select Event Configuration.
3. Add up to eight conversion events
Click Add Events, then select the eight gaming actions you care about most (for example, Completed Tutorial, Achieved Level, App Install/Download). Facebook AEM will only report these chosen events for users who opt out of tracking via iOS privacy settings.
4. Arrange events by priority
Drag each event into your preferred order, placing your highest-value action first. Facebook AEM always reports only the top-ranked event a user triggers, so rank bottom-of-funnel actions (e.g., Installs) above mid-funnel (e.g., Downloads, lead) and upper-funnel events (e.g., View Content).
5. Publish and allow up to 72 hours for propagation
After you click Publish, Facebook AEM applies your new configuration. Changes can take up to 72 hours to fully propagate and resume normal campaign learning.
Audit your existing Pixel events and remove any that don’t directly support your user acquisition goals. That way, Facebook AEM focuses only on the mission-critical conversions you need. Once the web setup is complete, integrate AEM into your mobile app environment.
App Implementation & Integration
To ensure accurate attribution and privacy compliance with your Meta ads, set up Facebook AEM as follows:
1. Setting up Facebook AEM for iOS re-engagement
Facebook AEM embeds campaign_id, adgroup_id, ad_id, and related identifiers into the deep link when a user taps your ad. Your in-app SDK reads these values on opening, and then Meta SDK (or MMP) reads campaign-level parameters appended to the deep link and sends aggregated postbacks via the AEM protocol.
What you do: Turn on the Re-engagement attribution option in your AEM settings; no extra coding needed.
What you see: All deep-link attributions appear in both your raw and aggregated data reports, including partial IP addresses by default.
Next, move on to app promotion settings.
2. Configuring Facebook AEM for app promotion
AEM is enabled by default during ad set creation for app installs. This allows you to collect AEM event data alongside SKAdNetwork metrics to view post-install behavior comprehensively. Selecting ‘SKAdNetwork only’ disables AEM postbacks for that Ad Set; optimisation will rely solely on SKAN signals.
Default selection: AEM runs out of the box with SKAdNetwork.
Manual override: Choose SKAdNetwork only if you need to disable AEM reporting.
Then, decide how broadly to share conversion data.
3. Enabling Advanced data sharing in Facebook AEM
Use the Advanced data sharing toggle to control whether AEM shares events only from ATT-consenting users or from everyone.
Toggle off: Only events from users who tapped “Allow Tracking” are sent.
Toggle on: AEM shares conversion events for all users, regardless of ATT choice, including masked IPs, anon_ids, vendor_id, and user-agent strings.
Before enabling this setting, check your privacy policies and local rules. Finally, confirm that your compliance workflows are updated. With AEM in place, apply these best practices to choose and order your events.
Best Practices for Event Selection & Ranking
When you set up Facebook AEM for your user acquisition campaigns, you must deliberate on which conversion events you surface and how you rank them. Follow these steps to make sure you capture the signals that matter most to your bottom-line metrics:
1. Verify your domain and configure exactly eight events
Before you choose events, confirm your domain in Meta Business Settings. Facebook AEM only allows eight conversion events per verified domain, so pick the actions that drive your core UA goals and add them in Events Manager.
2. Rank from bottom-funnel to top-funnel
Place your highest-value actions (e.g., Completed Tutorial, Achieved Level, App Install/Download) at the very top.
Next, slot in mid-funnel signals (Downloads, Lead).
Reserve the lower slots for awareness-stage events (View Content). This order ensures that, when iOS users opt out of tracking, Facebook AEM still reports the single most critical action you need for optimization.
3. Minimize event reordering
Whenever you change your event list, Facebook pauses your affected ad sets and triggers a 72-hour “cool-down” before new data begins flowing again. To protect your campaign's learning phase, only reorder when a business priority truly shifts.
4. Tie each event back to a UA metric
Whether you use Facebook’s standard events or custom conversions, pick events that map directly to your acquisition KPIs like cost per acquisition (CPA) or projected lifetime value (LTV). If you introduce custom events, make sure they reflect clear UA milestones (for example, a “Download”) rather than vague behaviors.
5. Test your attribution windows
Facebook AEM lets you select different attribution settings by event. Run comparative tests between 1-day click and 7-day click windows for each key action. Review which window better aligns with your funnel velocity; shorter windows often suit fast-converting offers, while longer windows can capture delayed decisions.
By following this structured approach, you’ll ensure Facebook AEM surfaces the right conversion events in the right order, preserves ad learning, and delivers the actionable insights you need to hit your UA targets. Now, let’s see how AEM stacks up against Apple’s SKAdNetwork.
When you compare Facebook AEM and Apple’s SKAdNetwork, focus on three key areas:
Scope
With Facebook AEM, you can track web and app conversions across all Meta placements without needing SKAdNetwork, so long as Meta Ads is your only traffic source. If you mix in non-Meta channels, you still must set up SKAdNetwork for those installs.
Flexibility
Facebook AEM gives you real-time insights and lets you pull aggregated postbacks into your MMP. You can choose between 1-day and 7-day click attribution windows (or test both) without hitting Apple’s install thresholds. SKAdNetwork, by contrast, enforces a minimum of 88 installs per day to unlock data and holds postbacks in a privacy timer, often delaying reporting by up to 72 hours.
Performance data
In a controlled test using Apple Custom Product Pages and the App Store Console for validation, Facebook AEM recorded 2,302 installs over one month versus SKAdNetwork’s 1,071 installs. That gap highlights AEM’s stronger event capture when users opt out of tracking.
If you encounter errors or gaps, use these tips to resolve them quickly.
Troubleshooting & Common Pitfalls
1. When you see “Missing opt-out events” errors in Facebook AEM:
Ensure IP masking is turned off in your MMP integration so that each postback includes a partial IP address, as required for re-engagement attribution. Then, verify your IDFA parameter matches Apple’s UUID format (128-bit identifier typically represented as a 32-hexadecimal digit string with hyphens), so Facebook can correctly parse opt-out events.
2. If events appear as ineligible in Facebook AEM:
Open Meta Events Manager, go to your app’s integration settings, and set the postback mapping to “All media sources.” Also, confirm you’ve selected MMP as the Preferred Connection Method. Include the required identifiers, such as campaign_ids for installs and anon_id or the standard ad_id/campaign_id fields from your MMP, so your events qualify for AEM processing.
3. Plan for rollout delays when Facebook AEM eligibility updates
After you adjust event mappings or switch connection methods, Facebook Ads may take 2–3 days to revalidate your app’s eligibility, and sometimes up to 7 days or more, depending on your MMP’s integration and Facebook’s phased rollout schedule.
The introduction of Facebook Aggregated Event Measurement (AEM) in response to Apple’s AppTrackingTransparency (ATT) updates has been pivotal in restoring critical conversion signals for user acquisition (UA). By allowing you to prioritize up to eight key events per domain, AEM ensures that your most valuable actions, such as ‘App Install’, ‘Level Complete’, and ‘Download’, remain visible even when iOS users opt out of tracking.
Verifying your domain and configuring events in Meta’s Events Manager is straightforward, but careful selection and ordering of events are necessary to optimize UA performance. Integrating the Meta Pixel, Conversions API, and SKAdNetwork mapping ensures robust data capture across web and mobile platforms while minimizing disruptions to your campaign learning phases.
Finally, comparing AEM against SKAdNetwork highlights AEM’s superior real-time insights and flexibility, making it an indispensable tool for privacy-compliant ad delivery and measurement optimization.
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FAQs
1. How do I verify my website to start using Facebook AEM?
You confirm ownership of your domain in Meta Business Settings, which lets you enable and configure AEM for that site.
2. Can I use Facebook AEM to track in-app events?
Yes—by adding the Meta SDK to your app, AEM can capture and report your key mobile events alongside web data.
3. What if I need to track more than eight actions?
You’ll need to group similar actions under one event or choose the top eight that drive your main conversion goals.
4. How can I test that my AEM events are firing correctly?
Use the Test Events tool in Events Manager to confirm that your chosen events trigger and report as expected.
5. How long does it take for changes in AEM settings to show up?
After you publish any new configuration, it can take up to 72 hours for your events and priorities to fully propagate.
