At which point during the campaign management timeline should an advertiser establish goals and KPIs?

Establishing goals and Key Performance Indicators (KPIs) is a foundational step that occurs during the "Setup" phase of campaign management. Before any campaign activities begin, advertisers must clearly define what they aim to achieve (goals) and how they will measure success (KPIs). This ensures the campaign is designed with a clear purpose and provides benchmarks for evaluating performance. Without clearly defined goals and KPIs at the outset, it's impossible to effectively "Optimize" the campaign, "Report" on its success, or conduct a meaningful "Review" later on, as there would be no criteria against which to measure progress or outcomes.