Hong has launched a campaign for his client which will run for 60 days. When is the earliest recommended time he should begin reviewing performance data toward optimization?

The earliest recommended time to begin reviewing performance data for optimization is 7 days. This allows sufficient time for the campaign to accumulate meaningful data, pass the initial learning phase, and for Amazon DSP's algorithms to optimize delivery. Reviewing data too early (e.g., 1 day) would lead to decisions based on insufficient and potentially unrepresentative data, while waiting too long (e.g., 10 or 30 days) could mean missed opportunities for early adjustments and wasted ad spend. Seven days provides a good balance for initial assessment and iterative optimization.