Problem here is Firefox is making big and sometimes wrong assumptions about what these so-called "tracking domains" do. That's not in any W3C spec -- that's Moz

Problem here is Firefox is making big and sometimes wrong assumptions about what these so-called "tracking domains" do. That's not in any W3C spec -- that's Mozilla attaching specific assumptions to specific parts of the Internet. Case in point: > One example is Google’s Page-Hiding Snippet, which may cause a web page to be blank for whole 4 seconds... Both the analytics.js and the test script are loaded from www.google-analytics.com, a tracking domain, for which we engage the tailing delay. Clearly if a domain is serving up an A/B test script then it is doing more than tracking. > Simply said some sites may need to be fixed to be able to adopt this change in scheduling. I have a problem with the term "fixed" here. Seems like Firefox's assumptions are what's broken here.