Every Q4 checklist tells you what to fix. Almost none tell you what to stop touching, or when the window closes. Every change resets learning, which costs a week in September and the quarter in November. What to fix now, what to freeze from mid-October, why September decides Q4, and the Australian dates most guides miss.

Every agency gives the same Google versus Meta framework, and it is not where businesses lose money. Meta overstates itself by two to three times while last-click attribution hands its branded search conversions to Google. Here is why that makes you cut the wrong channel, and what to fix before you launch either one.