What is ROAS in Google Analytics?

ROAS will replace the Return on Investment and Margin metrics that were previously available in Analytics. Return on ad spend metric calculates the amount of revenue earned for each dollar spent on AdWords. In Analytics the revenue is based on either e-commerce revenue and/or goal value.

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.