POV

POV: ITP2.1

Background:
Apple has released the latest specifications of its Safari tracking controls called ITP2.1 (aka Intelligent Tracking Prevention - part of WebKit, which is the open source browser engine that powers Safari). It further restricts Google and Facebook, both of whom switched to a first-party cookie/tracking method to avoid the effects of ITP 2.0.  

Changes will come into effect for the public once iOS 12.2 and Safari 12.1 come out of beta (expected to happen in the coming weeks), although researchers have already spotted the update in the wild, confirming a message from one of our ad serving technology partners that a silent release has happened (for testing).

Details and Implications:
The Apple WebKit developers made clear that the key motivation is to move towards eliminating cross-domain tracking, primarily referring to ad networks’ use of cookies to track multiple different websites to build a profile of user behaviour and interests. These are the key details:

All first-party cookies, including those used by many analytics platforms and much split testing software, are now capped to 7 days of storage (to clarify: authentication cookies, which have been properly implemented won’t be affected by the 7-day cap). This also means that the measurement of unique users in reporting, analytics and attribution might be impacted as the new limit will cause issues in how you can accurately define a unique user over a period longer than 7 days.

Additional changes are aimed at stopping those cookies from interfering with user-centric functional cookies (e.g. those used to record login status and “add to basket” functionality). This was not something that was widely reported as happening but was possible nonetheless with the increased workload expected of first-party cookies due to the changes made by Google, Facebook and others.

ITP2.1 will also stop third-party cookies (used by most ad serving / tracking companies) from being set at all. So, whereas in ITP2.0 a direct impression > click > conversion path was recorded, this will now no longer be recorded in the Safari browser. This effectively means many affiliates and third-party data sources will cease to track conversions/sales altogether.

Other updates focus on enforcing these new restrictions and preventing tracking companies from exploiting other potential loopholes in the browser/cookie systems.
Interestingly, Apple has also chosen to withdraw support in ITP2.1 for the "Do Not Track" signal (aka DNT, a user control enabling opt-out of tracking). DNT recently announced that the project was ending as Apple's research noted that most websites do not change their behaviour for users that have this feature enabled and there were companies that sought ways around complying with the user's wishes.

Summary:
The overall market impact will vary according to that market’s iOS market share, with countries like the Nordics expected to be more heavily affected, as they have a higher percentage of iOS devices. In general, brands currently using first-party tracking solutions with a 7 day or shorter lookback window should for the most part be unaffected. Brands using a longer lookback window will see a drop in their cookie pools for retargeting and audiences, as only users of 7 days or newer will be targetable. Brands using a third-party tracking solution will no longer see any conversions on Safari browsers, whereas they would have seen direct click to conversion events under ITP2.0.

Apple's claims to improve user experience and simplify cookie implementation for web developers could fuel speculation that other browsers may feel compelled to adopt similar measures (as Firefox did recently, while Samsung are also trialling with their latest beta version of their mobile browser Samsung Internet Beta 9.2) to retain their user base.

Further Reading: WebKit ITP 2.1 release / Mindshare Firefox and ITP 2.0 POV / ITP 1.0 POV / Samsung internet Beta v9.2