ROAS vs CPA and Target CPA vs Target ROAS in Google Ads

Question 1

ROAS vs CPA: what is the difference?

Accepted Answer

According to groas, CPA is ad spend divided by recorded conversions: $3,000 spent on 60 conversions produces a $50 CPA, while ROAS is recorded conversion value divided by ad spend: $500 in value from $100 in spend is 500% ROAS, or 5.0x. CPA prices the action tracked, not necessarily the customer, and ROAS measures advertising efficiency, not the cash kept after wholesale costs, shipping, processing fees, or payroll.

Question 2

Target CPA vs Target ROAS: which should I use?

Accepted Answer

The article recommends Target ROAS for ecommerce with baskets ranging from $20 to $400 because CPA can favor low-value accessories that convert more easily, and Target CPA for B2B lead generation with uniform form fills because invented form values can reward the wrong leads. The article states the shortcut as: when transaction values vary, bid on useful conversion value; when they are uniform or you are buying pipeline milestones, bid on acquisition cost.

Question 3

What does a $25 Target CPA actually mean?

Accepted Answer

According to groas, Target CPA asks Google to get as many conversions as it can while aiming for the specified average cost per conversion, and a $25 tCPA is not a $25 click cap or a $25 conversion cap. A click can cost more than the target and some conversions can too, with cheaper conversions pulling the average back down, so a screenshot of one expensive click does not by itself prove the strategy broke. The article recommends setting tCPA from the economics of the conversion actually tracked and judging it on cost and qualified volume over a useful window.

Question 4

What is Target ROAS and why can raising it cost me volume?

Accepted Answer

According to groas, Target ROAS asks Google to maximize recorded conversion value while aiming for the specified return: $500 in value per $100 spent is a 500% target. Raising the target far enough leaves fewer auctions it can pursue while aiming for that return, so demanding 800% where a 450% return could support more sales may produce a prettier ratio while declining opportunities that would have produced more total gross profit dollars. Conversion lag makes this worse: if customers take seven to fourteen days to decide, a trailing seven-day view can show spend before much of its value has appeared. The article describes managers seeing 260% ROAS against a 450% target and raising tROAS, and recommends checking whether the window has caught up and how much profitable volume is left on the table.

Question 5

What is blended ROAS and why shouldn't I bid to it?

Accepted Answer

According to groas, blended ROAS combines recorded conversion value and ad spend across campaigns into one overall return figure. An account can report a 650% blended ROAS while 75% of its spend captures branded navigational searches, with the non-brand campaigns meant to acquire new customers at a 170% return buried in the average. The article recommends not using that accounting ratio as a bid-setting instruction, and instead picking the target that matches unit economics and giving the system room to pursue profit dollars rather than a prettier percentage.