Target cost-per-acquisition (CPA) bidding can help drive conversions by using your conversion history and:
- cost-per-acquisition (CPA) goals to show the optimal ad when a conversion is more likely
- cost-per-click (CPC) goals to show the optimal ad when a conversion is more likely
- cost-per-click (CPC) goals to raise your bid when a conversion is more likely
- cost-per-acquisition (CPA) goals to raise your bid when a conversion is more likely
Target CPA bidding uses your conversion tracking data to avoid unprofitable clicks and get more conversions at a lower cost. Based on your campaign’s history of conversions, Target CPA bidding automatically finds the optimal cost-per-click (CPC) bid for your ad each time it’s eligible to appear. It sets higher CPC bids for more valuable clicks and lower CPC bids for less valuable clicks.
Target CPA is an AdWords Smart Bidding strategy that sets bids to help get as many conversions as possible at the target cost-per-acquisition (CPA) you set. It uses advanced machine learning to automatically optimize bids and offers auction-time bidding capabilities that tailor bids for each and every auction.
Read more here: https://support.google.com/adwords/answer/2390684