Facebook shrinks its ad conversion windows.

Facebook Changes Attribution Windows to Adapt to iOS 14 Updates

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Facebook shrinks its ad conversion windows.

Facebook is shrinking the attribution windows it uses to tie clicks and views to conversions produced by ads on its platform.

For now, the default attribution window will be 7-day click / 1-day view, not the 28-day click / 1-day view that it had been. As a result of the shorter timeframes, conversion numbers could decline for Facebook campaigns. 

Specifically, three attribution windows are being deprecated:

  • 28-day click
  • 28-day view
  • 7-day view


Also, advertisers will choose attribution windows at the ad set level going forward, not the account level. 

It’s all part of Facebook’s response to Apple’s new privacy-focused iOS updates. To remain in Apple’s App Store, apps will be required to ask users if they want to opt in to third-party tracking. App users will see pop-ups like this when they open an app on their iPhones:

While Facebook has already started showing the new pop-up, Apple won’t start enforcing the new rule until sometime this spring. 

Facebook is warning advertisers that, because so many users may opt out, it will be harder to personalize ads and receive in-depth performance reports. 

What Are Facebook’s New Default Attribution Windows? 

For new campaigns created after January 19, 2021, the default attribution window will be 7-day click / 1-day view — at least for the time being. 

When Apple starts enforcing its new opt-in rule, Facebook says it will change the default for new ad sets to 7-day click. (Though 7-day click / 1-day view will still be supported.)

The other supported windows will be 1-day click and 1-day click / 1-day view. Advertisers can select which window they prefer during campaign creation. 

There are some other exceptions to this, primarily around app-install campaigns. Facebook goes into more detail about that here. 

After Apple’s enforcement begins, Facebook Ads’ automated rules will shift to 7-day click attribution. Facebook recommends updating your automated rules to 7-day click now to prevent unwanted surprises later.


WEBINAR: What’s the Best Way to Measure Conversions?


What About Ad Sets Created Before Jan. 19? What Happens to That Data? 

For example, if you created an ad set before January 19, and it uses a 28-day window, Facebook will continue to use the 28-day window in its reporting for that ad set until Apple begins enforcing its opt-in rule. Facebook warns: 

  • After prompt enforcement [ from Apple ], we’ll no longer be able to support reporting for 28-day click, 28-day view and 7-day view windows in Ads Manager and Ads Reporting. When this happens, you can access historical data for these windows through the Ads Insights API. Note that the Comparing Windows feature will disappear once Apple enforces their ATT prompt.

It’s great that historical data will still be available. ChannelMix, Alight’s marketing analytics platform, can and does pull data through Facebook’s Ads Insights API, which it then stores in each client’s data warehouse. 

But we don’t know if there’s going to be an eventual cutoff for access to that historical data. Our team is reaching out to Facebook to get an answer about this and other questions.

What Else Is Changing Beyond Attribution Windows? 

The new attribution windows are just one facet of the changes that Facebook Ads are undergoing. 

For user devices running iOS 14, real-time reporting won’t be available. In some cases, there may be a delay of up to three days on data, Facebook warns. For web conversion events, Facebook will report on the time they occur, not the time of ad impressions they’re tied to. 

Advertisers will be limited to eight conversion events per domain. Facebook also won’t be able to give delivery or action breakdowns for web and app conversions

In some cases, Facebook may use statistical modeling for some attribution windows to account for a loss of iOS 14 data. Facebook says it will use in-product annotations to show when modeling is used. 

Our team is continuing to research the potential impact these changes could have on Facebook Ads reporting. If you’re a ChannelMix user who has further questions, please submit a ticket to Product Support.

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