The App Store’s original flaw

We no longer live in a world of nations and ideologies, Mr. Beale. The world is a college of corporations, inexorably determined by the immutable bylaws of business. The world is a business, Mr. Beale. It has been since man crawled out of the slime. -Arthur Jensen, NETWORK (1976)

The world’s first advertisement may have been a bronze plate used to promote a needle shop in China during the Song dynasty. The practice of advertising has flourished since then: advertising existed in ancient Rome, Egypt, and Greece, but its commercial utilization accelerated with the advent of the printing press in the 15th century. Radio advertising emerged in the 1920s; television advertising, in the 1940s; and digital advertising, in the 1990s. This paper finds that total advertising expenditure as a percentage of GDP in the US has remained roughly stable since the 1960s, across a number of measures of advertising expenditure. Advertising’s role in the global economy is persistent and substantial.

In The emerging marketing economist, I discuss the history of device identifiers on the iOS platform. From the piece:

The IDFA is a unique device identifier on iOS that is designed to be used for advertising purposes; the IDFA was introduced in 2012 as a replacement for the UDID, or Universal Device Identifier, which was deprecated in 2013. Detail about how the IDFA is used for advertising measurement and targeting can be found here. IDFA Zeroing complemented Limit Ad Tracking by giving it teeth: prior to the introduction of IDFA Zeroing, developers were asked to attest upon app submission that their app, as well as any third-party SDKs integrated therein, would honor a user’s Limit Ad Tracking setting, but enforcement was challenging and irregular. With IDFA Zeroing, Apple didn’t need to depend on willful compliance from developers: Apple retrofitted the existing LAT device with IDFA Zeroing setting to simply restrict access to the IDFA.

The UDID was deprecated in favor of the IDFA, and the IDFA has effectively been deprecated with Apple’s App Tracking Transparency (ATT) privacy policy. But it’s interesting to consider why the UDID and IDFA were introduced in the first place. While the UDID was designed as a generic, multi-purpose device identifier, the IDFA — or Identifier for Advertisers — was designed specifically to accommodate advertising measurement. A unique device identifier was needed for even the most basic form of install attribution on iOS because Apple made a consequential design decision with the App Store: to not allow any source information to be captured from link clicks to the App Store, as is the case with UTM parameters in web browsers.

Supporting the pass-through of campaign parameters from ad click to install would have allowed developers to attribute the source of installs to specific app promotion campaigns without needing to collect device identifiers at various points along the advertising journey. Apple’s design decision with respect to pass-through campaign data gave rise to an entire industry of advertising technology that serves no purpose other than to reconcile advertising clicks to installs using device identifiers, which I describe in The coming war between Apple and Facebook, published in 2017:

Before continuing to the 2016 implementation of LAT, it’s important to explain why the IDFA is relevant to advertisers. When an advertiser serves an ad on the desktop web, they can use the URL that the advertisement forwards to to capture a lot of information about that ad click: where the ad was served, from which campaign it was served, etc. This information is encoded in variables in the URL behind a question mark: you’ll often see strings like “?source=X&campaign_ID=Y” at the end of URLs. All of this data can be stored when the user reaches the click destination of the ad by the advertiser to help them attribute those clicks to various campaigns and calculate the return on investment of their marketing spend…That information can’t be encoded for mobile app install ad campaigns — or, at least, the platform operators won’t let it. So when a developer’s app is opened by a user, the developer has no background information on the provenance of that install. To alleviate this problem, an entire industry was born: mobile ad attribution.

Apple introduced SKAdNetwork, its native iOS attribution solution, in 2016; I covered it at the time in a piece called Will Apple redefine mobile advertising with SKAdNetwork?. (Google introduced native Android attribution to Firebase, its Android analytics platform, in 2017, although Google Play supported UTMs from advertising campaigns prior to that). My assessment at the time that Apple’s introduction of SKAdNetwork was momentous proved correct, although not for a number of years: the use of third-party, IDFA-based attribution was widespread and entrenched in 2018, and SKAdNetwork didn’t become relevant as an attribution solution until ATT was deployed in 2021.

In The IDFA is the hydrocarbon of the mobile advertising ecosystem, I argue both that:

  1. Excising the IDFA from the iOS platform was necessary if not imperative, and that;
  2. Apple’s motivations for doing so through ATT were primarily economic.

My dissatisfaction with ATT is rooted in the fact that it privileges Apple’s own ad network, it doesn’t provide consumers with genuine choice, and that early versions of SKAdNetwork were unnecessarily, and seemingly purposefully, underpowered for the intended use case.

Ned Beatty plays Arthur Jensen, a caricature of an avaricious media mogul, in the 1976 film NETWORK. But the quote above from his character’s dark but memorable monologue would likely not have been out of place in the board room of an ascendant social media company in the early aughts. The App Store’s original flaw was introducing a device identifier that could be commandeered in the way that the IDFA ultimately was.

Had Apple introduced a native attribution solution with the capabilities of the current version of SKAdNetwork at the outset of the App Store, or even a few years into the smartphone supercycle, both the privacy concerns related to the IDFA as well as the depredations of ATT could have been mitigated. Simply offering native attribution could have forestalled the privacy concerns inherent with persistent, universal device identifiers.