Home » A primer on iOS 14.5’s impact on Facebook audience building (and what to do about it)

A primer on iOS 14.5’s impact on Facebook audience building (and what to do about it)

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I’ve read a lot of bullshit regarding the impact of Apple’s notorious iOS14.5 update. It’s a fairly technical & complex matter, yet most articles on the subject are clickbait or just content for the sake of being content, often written by a junior content marketer. Consequently, I couldn’t resist finding out the details myself and synthesizing my findings in this blog post.

To appreciate this blog post, you should at least grasp how tracking pixels work. If you’re a marketing technologist or web analyst, this should be right up your alley.

⛔ This blog post is not about the impact of iOS14.5 on showing personalized ads inside apps. Short story: if a user does not accept being tracked by Facebook via Apple’s default App Tracking Transparency (ATT) Pop-up, the app cannot access the Identifier For Advertisers (IDFA). Ergo, Facebook cannot identify the user and consequently, cannot serve personalized ads. Attributing conversions to campaigns can still be done via Apple’s SKAdNetwork — yet limited.

⛔ This blog post is also not about the impact of iOS 14.5 on the functioning of Facebook’s Audience Network (FAN). Short story: I think FAN has become useless on iOS devices, and I’m really interested to see how Facebook will response.

✅ This blog post is about the impact of iOS14.5 on tracking user behavior on your website, sending it to Facebook via its pixel, and using it for audience building (such as retargeting).

What’s the big deal?

What you would normally expect of a tracking pixel.

This aspect is impacted by Private Click Measurement (PCM). It is a “Webkit development to enable privacy-friendly tracking. It should prevent the collection of personal data and at the same time enable conversion tracking with reference to a clicked ad – even if the user has not consented to the consent banner.”

In other words, WebKit browsers such as Safari will block calls to social media tracking pixels and provides developers and marketers with PCM, a privacy-friendly tracking alternative.

How it works: a link element on a (social media) website can be decorated with a domain and a campaign ID, to which potential conversions on the destination website can be attributed over the next seven days.

This is the example from the WebKit website.

<!-- Link on social.example --> 
<a href="https://shop.example/product.html" 
   attributionsourceid="[8-bit source ID]"
   attributeon="https://shop.example">
	Link text
</a>

Later (within 7 days), when a specific event is triggered an attribution report is scheduled to be sent randomly between 24 and 48 hours later or any time thereafter when the browser is running. You should know that users can opt-out of these attribution reports.

How PCM works.

😕 But, I don’t see these HTML attributes in Facebook source code when I inspect an ad.

(Another acronym incoming!) That’s because, in anticipation to PCM, Facebook has developed Aggregated Event Measurement (AEM). In line with Apple’s guidelines, (1) it limits identification,
(2) its metrics are only available as an aggregate and (3) its reporting is delayed (basically, when it receives the attribution report from Apple). WebKit’s formal implementation guidelines aren’t visible client-side and (I assume) are implemented on Facebook’s servers.

AEM requires advertisers to verify their domains, limit the number of tracked conversions to 8 and limit the maximum number of campaigns.

We can conclude that:

  • Attributing conversions to campaigns is facilitated by the PCM framework. Consequently, reporting is slower, and involves less customer metadata.
  • The attribution lookback window is limited to seven days.
  • Retargetting your own website visitors is no longer an option.
  • Facebook’s targetting features might be less accurate, as iOS 14.5 users’ profiles will contain less behavioral data.
  • If you understand what I explained, you should see that UTM tracking is in no way affected.
  • With Chrome for iOS running on WebKit, I assume Chrome users on iOS are also affected.

The workaround

Honestly, I’m not a big fan of Facebook myself. So I can only applaud Apple’s (opportunistic) efforts. However, the nerd inside me couldn’t resist finding out what the workarounds are.

Short story: you really need real-time attribution of conversions, and you want to break your reports down by a multitude of dimensions — down to the individual level, there’s still a workaround. It’s called server-side tracking. Tealium has a concise overview of server-side tracking.

It basically comes down to taking the call to the Facebook servers on a specific conversion out of the user’s browser by masking it as a call to the website’s server, from where you relay it to Facebook using the Conversions API.

Implementing the FB tracking pixel is even optional. However, by not doing it, you’ll lose some power to identify a user, because you won’t be setting Facebook’s user ID cookies (_fbp and _fbc) anymore.

How “true” server side-tracking works.

However, implementing (true) server-side tracking is extremely hard. Not from a technological perspective, but from an organizational perspective. Implementing client-side is fairly easy, even without a tag management solution: you give a developer some snippets, (s)he implements it, and you can debug it inside your browser’s inspector. You can see whether the snippet is implemented correctly and you inspect whether the call happens. But tracking that’s implemented on the side of the server is basically a black box if you don’t have access to the source code.

That’s why there are server-side tracking and container solutions such as Tealium EventStream and Google Tag Manager’s server containers (FYI: Using CNAME cloaking, you can even make first-party calls to those solutions). These new technologies are the go-to workarounds for technical marketers that want to circumvent Apple’s latest privacy moves.

How a CNAME cloaked server-side container works.

There are some great tutorials available for setting up server-side FB tracking.

Good luck!

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