<b>Lowest-cost bidding will overpay for trash. Cap it.</b>

<b>Lowest-cost bidding will overpay for trash. Cap it.</b>
Scaling on lowest-cost → spend ballooned, CPA crept from $30 to $52, algo chasing junk clicks. Switched to a bid cap at $35 → volume dropped 15% but CPA locked at profit. You trade a little reach for a guardrail. When margins are tight, the cap is your seatbelt → set it slightly above your true CPA and let it filter the garbage out.