Cost-cap bidding holds CPA within ~8% of target but leaves 20-35% of available volume on the table

Cost-cap bidding holds CPA within ~8% of target but leaves 20-35% of available volume on the table

Cost cap = you set a max average cost; lowest-cost = uncapped, spend the budget.

Bid-strategy A/Bs, 22 accounts:
— Cost cap CPA variance: ±8% around target ▼ (tight)
— Lowest cost CPA variance: ±26% (wide), but 28% more conversions
— Cost cap set too tight (