Which bidding strategy should use you if you want to increase revenue from your ad spend?
Enhanced cost-per-click (ECPC)
Target cost-per-action (CPA)
Target return on ads spend (ROAS)
Target ROAS lets you bid based on a target return on ad spend (ROAS). This AdWords Smart Bidding strategy helps you get more conversion value or revenue at the target return-on-ad-spend (ROAS) you set. Your bids are automatically optimized at auction-time, allowing you to tailor bids for each auction.
Read more here: https://support.google.com/adwords/answer/6268637