I stumbled across an article that notes how marketers are already adapting to this tech: "
How Apple’s Intelligent Tracking Prevention works & why Google/Facebook could benefit most". This article references a blog article from John Wilander "
Intelligent Tracking Prevention". That WebKit article talks about a 24-hour window where "cookies can used in a 3rd party context". The MarketingLand article speculates about which providers and advertisers will be able to exploit that 24-hour cross-cookie window.
"The one-day window opens a key opportunity for the web’s most popular services and the companies that control them and puts the ad tech companies with which users don’t have direct interactions at a clear disadvantage. Or as Curt Larson, VP of product at Sharethrough, put it, 'It helps them [Google and Facebook] in the fact that it hurts everyone else.' "
I sure as heck hopes that Apple gives a way to shrink that window -- to nothing.
There's also some doubt that these changes will matter:
"Privacy advocate Alexander Hanff said in
a blog post that server-side scripts are able to gather the same information even if they are not loaded in Safari, and that while Apple’s efforts are welcome, 'it is highly probable that Apple’s new approach to tracking will only accelerate a move to these server side technologies from those who have yet to use them.' "
Maybe it's time to shift all browsing to a VPN provider.