Since iOS14.5 and the deprecation of the IDFA, measuring the impact of growth campaigns has changed dramatically on iOS. Gone are the days when real-time, user-based attribution was as easy as the click of a button.

Today, all app install and tracking has to go through SKAdNetwork under Apple’s AppTrackingTransparency (ATT) framework. This has had a massive impact on campaign attribution methods like view-through attribution (VTA).

In this blog, we dive deep on how growth marketers are measuring VTA for their ad creatives post-IDFA, including the methods that are working and the technology behind them.

View-through Attribution: A Review

View-through attribution (VTA) is a valuable way to track the engagement of your campaigns, especially when it comes to your retargeted ads. VTA uses impression tracking to give credit to a campaign for a conversion. It does this by tracking the user from ad impression to conversion, even if the user didn’t engage with the ad beyond viewing it. In this way, view-through conversions can help you determine the value of your advertising as a demand gen driver.

Prior to iOS 14.5, VTA conversions generally accounted for up to 70% of prospecting conversions and 50% of retargeting conversions.

VTA vs. CTA

There have, historically, been two major ways to track engagement: view-through attribution and click-through attribution (CTA).

For reference, CTA has generally been the simplest and more straightforward method. In CTA, an ad gets the credit for a conversion when a user clicks on it and then at some point within the attribution window — converts.

On the other hand, in VTA, an ad gets credit for a conversion if it shows up on the same page a user is on. The model assumes the user “sees” the ad and then makes a purchase because of that. The value of VTA lies in its recognition of today’s multichannel landscape in which the user experiences more touch points than ever before. People don’t engage with brands only once through a website. They interact with brands in multivariate ways via social media, mobile apps, and other on-and-offline channels.

VTA in the post-IDFA World

As mentioned above, following the rollout of iOS 14.5, now all app install and tracking goes through SKAdNetwork. SKAd is Apple’s own tracking solution that provides an alternative to deterministic attribution when users opt out of sharing their personal data with an app. While SKAd does provide some basic reporting, it’s not as granular as what MMPs have historically provided.

The new age of data privacy in which device IDs like the IDFA are harder to come by, there is no real-time or user-based attribution. That being said, alternatives have been innovated — like probabilistic attribution — that are also compliant with Apple’s ATT framework.

View-through Attribution using SKAdNetwork 

On a high-level, VTA on SKAdNetwork works like this: a user sees a rendered ad for three or more seconds. Then, the publisher fires an impression to Apple with the signature of the ad server. This occurs at the exchange level, so exchanges have to make changes to their SDKs to support VTA supply.

Before running VTA retargeting campaigns, it’s critical to test SKAd. This includes reviewing how different exchanges are handling VTA measurement and reporting, and building your own strategy for postback and conversion management to fill any gaps.

View-through Attribution using Probabilistic Attribution 

As mentioned above, probabilistic attribution is a form of mobile attribution that does not rely on the IDFA. Instead, it provides an alternative to deterministic attribution by relying on probabilities. In this way, it also respects the guidelines set out in Apple’s ATT framework.

Probabilistic attribution works under the assumption that even if a user does not share their IDFA, there is a set of probabilities that one or more campaigns drove the install. This attribution model is based on patterns and relies on machine learning to identify probable conversions. MMPs look at parameters (i.e., time of click, time of install etc.) and use them to make an estimate of the source of an install after a click.

After over a year since the introduction of ATT and SKAdNetwork, it has been noted that the probabilistic attribution method is a valid alternative to SKAdNetwork and is effective at optimizing app install campaigns, improving models, and driving ROAS.

For example, it’s possible to test and collect data for multiple creative variants across multiple publishers with VTA enabled. Through VTA, ad impressions are collected and fed back into models. This marketers allows marketers to make more precise predictions on install probability, cost per install (CPI), and retention rate (RR). As the predicted probability increases, models can start bidding on higher CPM tiers, driving better conversion rates and higher-quality users.

Takeaways on View-through Attribution Post-IDFA

Much has changed since the rollout of iOS 14.5. Most notably, the way growth marketers measure the attribution and value of their campaigns and ad creatives.

  • What is view-through attribution? An attribution method that uses impression tracking to give credit to a campaign for a conversion. This method tracks a user from ad impression to conversion, even if the user didn’t engage with the ad beyond viewing it.
  • VTA in the post-IDFA world.  Following the rollout of iOS 14.5, all app install and tracking goes through SKAdNetwork. SKAd is Apple’s own tracking solution that provides an alternative to deterministic attribution.
    • View-through Attribution using SKAdNetwork: A user sees a rendered ad for three or more seconds. This results in the publisher firing an impression to Apple with the signature of the ad server.
    • View-through Attribution using probabilistic attribution. One alternative that’s been innovated in the years since iOS 14.5’s rollout is probabilistic attribution. Probabilistic attribution works under the assumption that even if a user does not share their IDFA, there is a set of probabilities that one or more campaigns drove the install. As predicted probabilities increase, models can start bidding on higher CPM tiers, driving better conversion rates and higher-quality users.

Learn more about the value of VTA to your retargeting campaigns

VTA can be a valuable way to attribute the re-engagement of your app to retargeted ads while also taking into consideration other marketing initiatives, your brand awareness and the strength of your creatives. Read more about the value of VTA to your re-engagement campaigns in our blog post here.