On December 10th, Webkit posted a blog about changes to the newest versions of Safari on iOS and iPadOS 13.3, Safari 13.0.4 on macOS Catalina, Mojave, and High Sierra. These changes where targeted to make it harder for websites to detect that ITP was in effect, thus reducing its viability as a fingerprinting vector.
The above plays out with the following changes:
- The Storage Access API Takes the Underlying Cookie Policy Into Consideration
- Absence of Cookies In Third-Party Requests Does Not Reveal ITP Status
This was not all the update contained however, it also further cemented the fact that websites should use 1st party cookies with this change:
- All Third-Party Cookies Blocked on Websites Without Prior User Interaction.
Finally, in what will affect reporting the most – Safari will now do the following:
- Origin-Only Referrer For All Third-Party Requests
So if you were hoping to optimize your referral traffic to specific pages this holiday season, you’re going to be in for a rough time where Safari is concerned as this turns a referrer like:
Site.com/really/awesome/page
to
Site.com
Limiting you to the previous domain. This becomes especially problematic if you leverage AMP (Accelerated Mobile Pages), as with the way the AMP cache works, anything served from the cache will likely be classified as the cache domain only (which is the same for everything in the cache). This will result limited (to no) insight in to which AMP powered pages are sending you inbound traffic.
With this being the case, and other browsers planning to follow suit – I consider it very risky to rely on the referrer field for any mission critical functionality as it will increasingly become unreliable. Should you need the referring domain, you’d (given the current tech landscape) have to figure out a way to have the referrer passed as a name/value pair on the inbound link.
As we close off 2019 it should be clear with the slate of pending changes set for early 2020 that analytics will become an even more complex and divided place with real impact to reporting and the bottom line. I feel 2019 should have made clear that analytics will require ongoing maintenance going forward, and would recommend that organizations consider what that means for their 2020 fiscal planning.