A CTR above 2% is strong for ecom Facebook ads. Industry average is around 0.9% — if you're below 1%, focus on creative before touching targeting or budget.
CPM varies wildly by audience — cold traffic is always more expensive. Retargeting audiences typically have 3–5x lower CPM than cold prospecting, which is why warm audiences convert more efficiently.
ROAS alone is misleading without knowing your break-even ROAS. A 3x ROAS sounds great — but if your margins are thin, break-even might be 4x. Always anchor ROAS to your actual cost structure.
CPC matters less than CPA — cheap clicks that don't convert are worthless. A $0.20 CPC with a 0.5% conversion rate is worse than a $2.00 CPC with a 5% conversion rate.