Once a product has accumulated enough sales history — roughly 3–5 months on-sale or 1,000+ units sold — stop trying to manually target or infer customer demographics and instead trust Amazon A9 Algorithm to route the listing to the right buyers on its own.
Manual demographic targeting is treated as a pre-data-maturity workaround, not a permanent strategy: below the threshold there isn't enough signal for the algorithm to optimize well, so more manual involvement is warranted; above it, Amazon's own matching outperforms manual guesses. Contrasts with Brand Analytics Demographics Tool (Customer Avatar), which is a research tool for understanding buyers rather than a targeting override.