26 April 2021

Ready your Facebook Advertising Measurement for Apple iOS14.5+ privacy enforcement

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If your business runs Facebook advertising campaigns, then you’ll want to be paying attention to the latest set of privacy changes which are due to be enforced within the next week. At the time of writing, Apple has just confirmed that the roll out of iOS 14.5 will go live in the week commencing 26th April 2021.

The introduction of the latest operating system signifies a landmark for the enforcement of new privacy policies that have the potential to cause significant disruption to your Facebook advertising campaigns, especially if you don’t take the recommended actions prior to launch.

So what’s happening?

Apple has been on a crusade to increase user privacy online as far back as 2013, but things really started ramp up with the introduction of ITP (intelligent tracking prevention) which launched back in September 2017.

We’ve previously commented on these privacy updates in Apple announce major Safari privacy changes, Safari tightens the ITP screws again and ITP and iOS 14 - Apple Just Made 10 Louder.

But with the official launch of iOS 14.5 on the horizon, this update also serves as a deadline for when app developers must comply with new App Tracking Transparency rules (refer to 2:26 timestamp). As you can imagine initially Facebook wasn’t too pleased with these changes, but it appears that Facebook has now accepted that rather than fight the changes, they must learn to adapt to them moving forward.

The changes are multifaceted, so we’ll touch on the following topics as we go:

  • Apple’s App Tracking Transparency (ATT) framework and how it will affect app based conversions

  • Apple’s Private Click Measurement (PCM) framework and how it will impact web based conversions

  • Facebook’s Aggregated Event Measurement

  • And finally how these changes will impact reporting abilities going forward

iOS App Tracking Changes

Apple’s App Tracking Transparency (ATT) framework

Perhaps the most visible change to users will take the form of a new prompt when installing an App via the Apple App Store. This type of prompt is not necessarily new, in that you often need to grant an App specific device permission when installing, for example to: ability to read contacts, access the mic or camera etc. But, what is different about Apple’s ATT is that this permission approach now applies specifically to cross site -> app tracking and analytics data collection in general.

An example of the tracking request notification

Prior to Apple’s ATT changes this kind of analytics based tracking would occur silently in the background with most app users none the wiser, and only the most technically savvy or dedicated enough to read through t&c’s and or privacy policy pages would have an inkling as to what was happening. But based on studies that have found 1% or less actually do read such pages, we can assume that’s definitely the minority of users.

By placing this opt-in upfront and asking for user consent in advance it’s fair to assume that more users are now likely to opt out of tracking on iOS 14 devices. This will in turn hinder the ability of ads personalisation features and performance reporting will be more limited than it was prior to this update.

What action should you take?

If you run App Install based campaigns, or you drive users to your iOS based Business App via Facebook campaigns, you need to perform the below actions to prepare for the update:

  • Upgrade the Facebook App SDK to version 8.1. This latest version of the SDK supports Apple’s SKAdNetwork API and enables measurement of app install ads.

  • Configure Apple’s SKAdNetwork in Facebook Events Manager using one of the three listed options, (the option you pick will depend on the way your app communicates back to Facebook).

  • Define the priority of collected events in terms of importance to your business. Since only the highest priority event will be sent and reported back when there are multiple customer actions recorded during a conversion window.

  • Ensure the advertiser tracking-enabled flag is being sent with all app events to attach user consent status information to each event. This is how Apple/iOS will be able to regulate when event data can be reported back to platforms such as Facebook.

What’s changing for web based conversions?

If you measure web based conversions from Facebook campaigns, iOS 14.5 will bring with it further disruption in the ability to track user activity.

For a quick recap of the iOS based changes that have already taken place prior to the iOS 14.5 update refer to: ITP and iOS14 - Apple Just Made 10 Louder.

In short what this has meant is that third party cookies used by the likes of Facebook pixel tags to track user activity across domains (an example conversion journey which looks like: Facebook.com → YourDomain.com → Conversion), became more challenging without third party cookies.

Apple’s PCM

Since our previous post on ITP and iOS, Apple has introduced Private Click Measurement (PCM). At a high level Apple says:

“Safari now includes the ability to offer Private Click Measurement, an innovative way of doing ad click measurement that prevents cross-site tracking but still enables advertisers to measure the effectiveness of web campaigns.”

The basic idea behind PCM is that web-tracking should remain anonymous, but Ad Networks such as Google and Facebook should still be able to report back on clicks and conversions. Except PCM won’t rely on cookies or give these platforms the ability to track user activity across multiple domains or websites.

And unlike ATT used in app tracking, no user prompt will show for each website that uses PCM to monitor conversions and event tracking, since this is considered a browser based setting (not a specific website setting).

Apple’s plan is that eventually PCM will become a standard measurement framework which will apply to any web browser installed on an Apple iOS device.

So whilst it seems that tracking may get tougher without third party cookies in some respects, there is a silver lining to Apple’s PCM change which was introduced in the iOS 14.5 Beta - PCM will now support cross environment measurement such as App to Web measurement.

This means that clicks from the Facebook app (not just the Facebook website) will also be attributable to a specific click. This was difficult if not impossible to do previously when relying on third party cookies for conversion measurement.

How Apple’s PCM attempts to achieve user privacy

  • Aggregated reporting - PCM will limit reporting to the campaign level only, i.e. this conversion action is attributed back to the campaign ID that drove the click. The total number of reportable campaigns is limited to 256 variations.

  • The 265 unique campaign ID restriction is to stop advertisers from abusing campaign combinations to try and track personal usage.

  • PCM also limits the conversion actions that can be reported to 16 (distinct actions), and these actions cannot report on specific products, revenue data or carry other meta data type information.

  • Deliberately delayed reporting - The last piece of the PCM puzzle, which is a fairly simple but effective mechanism. Where a random 24-48 hour reporting window is used to send conversion data back to the platform in question. This is done so that an advertising platform can’t reverse engineer the timestamp to identify specific site visitors.

Facebook is embracing PCM measurement

To adapt to Apple’s PCM driven changes, Facebook has introduced what’s called Aggregated Event Measurement, and in a similar vein to PCM will also limit domains to eight conversion events that can be used for conversion optimisation. Advertisers will need to select which of these eight conversions to optimise against as part of their campaign strategy.

Facebook has stated that: “Aggregated Event Management is analogous to Apple’s Private Click Measurement, but is designed to solve for key advertiser use cases not addressed by Apple’s proposal. Aggregated Event Measurement will continue to evolve with upcoming browser changes to help our advertisers support consumer privacy.”

What action should you take?

For Facebook’s web based pixel tracking, you should take the following steps if you haven’t yet:

  • Verify your domain via your business manager account. This will enable Facebook to determine the correct owner of the domain for reporting purposes. This can be done via HTML file upload, DNS change or meta tag updates.

  • Select your top eight conversion events per domain and set their priority against each other. You can access them in your UI via this configuration link. You can also learn more about configuring events here.

  • Important! Choose carefully, since any further changes to the order of conversion priority may cause your campaigns to be paused for up to 72 hours with each change.

Why does this campaign pause need to occur?

Facebook has explained that A 72-hour pause is to allow for 1 day to attribute an event after a click, and between 24 and 48 hours for the event to be reported.

The idea is that this helps minimise data inaccuracies. Also during this time period, any updated conversion events won’t be available for optimisation or reporting.

We presume this pause is necessary because of the restrictions introduced via Apple’s PCM and this change could disrupt and throw off any machine learning algorithms Facebook employs to help you with campaign optimisation.

  • Paused ads and ad sets won’t restart on their own after the changes are applied, so you must restart them in Ads Manager after the 72-hour reset period is over.

  • Failure to action these steps may result in your ads being paused.

    Editing event priority in the Facebook event UI

    Editing event priority in the Facebook event UI

What are the expected reporting limitations you’ll see going forward?

It’s important to note that the configuration and account limits imposed by Aggregated Event Measurement won’t apply until Apple begins to enforce their iOS 14 changes. 

However it should come as no surprise that a consequence of the Apple iOS 14.5 change is increased reporting limitations around Facebook activity. This is due to the reliance on the Apple SKAdNetwork API for App install reporting and Apple’s PCM for web based conversions.

So let’s look at what some of these changes are:

Delayed reporting changes

Reporting data may now be delayed by up to 72 hours or three days. For iOS 14 app install campaigns, conversion events will be reported based on the time that they are reported to Facebook by the SKAdNetwork API and not the time they occurred.

Web conversion events will be reported based on the time the conversions occur and not the time of the associated ad impressions.

The knock on effect of delayed conversion reporting may also have a downstream affect on machine learning and conversion optimisation algorithms, which is one of the reasons mentioned above that ad campaigns will be paused when re-assigning your event priority.

Estimated results

Since not every user will opt-in or consent to tracking, Facebook will attempt to estimate what those user conversion numbers would look like if they did opt-in via machine learning.

  • App Install campaigns: reports will only be at a campaign level with ad set/ad breakdowns inferred from statistical modelling.

  • Web conversions: statistical modelling may be used to account for conversions from iOS 14 users who opted out of tracking.

Segmentation limits

Demographic, geographic and or device type breakdowns will no longer be supported for conversion reporting, this is in part due to Apple’s limitations around sending additional meta data with conversion events. This will make campaign optimisation more difficult, since you won’t be able to slice and dice conversions as easily as before.

Attribution windows just got smaller

These windows will be set at the Ad Set level and will default to a 7-day click attribution window, reduced from the older 30 day window. View through activity may be limited down to one day only.

Report limitations per Domain

You can now only report conversions from one website domain per ad. Third party cookies previously enabled you to measure one ad click and attribute multiple conversions across multiple domains.

Creative optimisation

With reporting limited to the campaign level only and extrapolated to the Ad Set (i.e. Modelled Conversions), optimising a specific Ad and its creatives will become difficult if not impossible.

For example: You may wish to restructure your account to have one specific creative per App install campaign (similar to the Google Ads controversial practice of Single Keyword Ad Groups aka SKAGs). However Facebook does have relatively low limits around the number of ad sets per account, which may ultimately limit how effective this is for you.

Moving forward

While for some of you trying to optimise the effectiveness of your campaigns, these limitations may be frustrating, it’s important to keep in mind that measurement frameworks like Apple’s PCM and Facebook’s response via Aggregated Event Measurement are still in the early stages of development, and we can picture new methods being developed to help fill the void left by third party cookies. Ultimately a more private web experience is better for everyone long term, but with any change, we do expect short term pain and speed bumps as we navigate through this industry transformation.



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Gavin Doolan is a Consultant at Louder specialising in web analytics technology and integration. He views the future of analytics and business intelligence as being driven by Big Data and Machine Learning. In his spare time he enjoys fixing/restoring vintage cars, gardening, spending time with the family and walking his dog “Datsun” around local nature reserves.