Apple’s Attribution Fix For Safari Explained

  • When it comes to ad tracking in Safari, Apple usually taketh away. But sometimes Apple giveth advertisers a little something. Meet privacy-preserving ad click attribution for the web.

    Think of it as Apple throwing a bone to advertisers who need a way to measure the effectiveness of their ads in Safari, which is where tracking cookies go to die.

    The ad click attribution API, released as an experimental feature in early May, enables a limited form of click-to-conversion tracking that is built directly into the browser itself. It doesn’t rely on cookies and severely restricts the amount and type of data that can pass between buyers, sellers and third-party intermediaries.

    For now, the feature has to be manually enabled and is only available within a preview version of Safari, where users and developers can experiment with new tech and extensions. But the plan is to set it as the default in Safari later this year.

    Apple is also proposing the approach as a standard to the World Wide Web Consortium in the hope that other browsers adopt it, too.

    Nothingburger vs. the future

    Specifically, advertisers will be able to see if a certain ad campaign led to more purchases, but there will be no way to uniquely attribute ad clicks and conversions to specific people.

    “Apple wants to prevent tracking, but they see that the advertising ecosystem does need the ability to track conversions and attribute them to clicks,” said Andraz Tori, CTO and co-founder of Outbrain-owned Native DSP Zemanta.

    But the overall trend is clear: The way in which third-party tracking functions on the web is changing, and not just on Safari. Firefox and Chrome are also making moves of their own to curtail third-party cookies and fingerprinting.

    The jury is out, however, on whether this particular ad click attribution experiment by Apple is a nothingburger …

    “This is not technology that would be appealing or easy to adopt for anyone in the current ecosystem,” said Ari Paparo, CEO of Beeswax.

    … or if it’s the next best thing since sliced bread.

    “Every browser will do something like this,” said Zach Edwards, founder of analytics firm Victory Medium. “This is definitely the future: Server-to-server and on-device privacy scrubbing is lovely.”

    How it works

    The standard way to do click attribution, Tori explained, is for an ad tech vendor to drop a cookie by quickly redirecting to its own domain after someone clicks on an ad. When that person later visits the advertiser’s website, a tracking pixel picks up on the cookie and the click is attributed to the conversion.

    This setup doesn’t fly on Safari, which has long blocked third-party cookies by default, and now, via Intelligent Tracking Prevention, treats first-party cookies that have tracking characteristics with great suspicion.

    Most recently, Safari eliminated the link decoration loophole, which means third parties can no longer append extra information to a click URL in an attempt to use it as an identifier.

    Paparo summed it up thusly: “If you’re click-based in Safari, you’re shit outta luck.”

    Apple’s ad click attribution API serves as a fix, but with very clear constraints.

    Ad clicks are stored by the page hosting the ad at the time of the click, and only for a limited period of time, via two new attributes: adDestination and adCampaignID. Advertisers can match conversions, such as adding an item to a shopping cart, signing up for a newsletter or actually making a purchase, against these stored ad clicks using good old tracking pixels.

    The difference is that the conversion is reported directly to the browser, rather than the referring URL. The browser then reports that a conversion happened for a user who previously clicked an ad, but nothing more specific than that.

    Even though the API calls happen instantly, there will be a random delay of between 24 and 48 hours in reporting conversions, which makes it much harder to use fingerprinting tactics that tie parameters like IP address and browser type to conversions, Tori said.

    The API also restricts the number of ad campaigns that can be measured simultaneously and the number of conversion events on an advertiser’s website to just 64, which makes it extremely difficult to do granular tracking at scale.

    The move is conceptually similar to SKAdnetwork, a test API Apple released in March 2018 that allows ad networks or advertisers to attribute installs directly from the App Store without having to rely on a third-party attribution vendor.

    What does it mean

    Privacy-preserving ad click attribution for the web might position itself as a fix, but it also raises a lot of questions.

    Because clicks and reported conversions can only be tracked by first-party websites, “ad tech is immediately out of the picture,” Paparo said, although a first-party analytics provider, like Google Analytics, might still be able to function.

    But publishers will have to track clicks on their own domain, rather than an ad server domain, which won’t be easy to architect. “Will The New York Times really have to set up every campaign in their own domain, and how does that scale?” Paparo said.

    And while affiliate marketers should be fine, because basic conversion data is all they need to get paid, this data “isn’t very useful for large modern publishers,” he said.

    “How many scaled advertisers and their publisher partners care about a direct click to conversion as the key driver of the money they spend in digital?” he said. “That is the only problem this solves, and it isn’t how they optimize, so this solution will only help a tiny piece of the overall advertising market.”

    Then again, that’s not really Apple’s concern.

    “This finally creates a data architecture that makes it possible for someone to turn off link click attribution and it fixes mass privacy violations,” Victory Medium’s Edwards said. “ITP 2.0 already blocked cookies and made tracking basically impossible – this proposal is Apple fixing cookie tracking, but not by just turning it back on.”

    But does this have a chance of widespread adoption? Apple is clearly hoping for pickup with WC3. The past, however, could be an unfortunate indicator of the future, said independent ad fraud researcher Augustine Fou.

    “It is a great idea and it will help consumer privacy,” Fou said. “But as we have seen for years now, good ideas that help privacy or reduce fraud [while going] against the money-making machinery of ad tech will simply be ignored, delayed, suppressed or argued against for another seven years – like viewability – until it practically dies on the vine due to lack of adoption."

    Online Advertising