Amazon PPC glossary
ROAS (Return on Ad Spend)
ROAS is ACOS turned upside down. Instead of asking what share of a sale went to ads, it asks how many sales dollars each ad dollar produced. A higher ROAS is better.
Example
You spend $20 and your ads bring in $80. ROAS is $80 divided by $20, which is 4. That is the same result as a 25% ACOS. You can convert between them: ROAS is 1 divided by ACOS.
Where it matters most: Book 1, The Amazon PPC Clarity Guide, in the chapter “Scaling Strategies.”
Work out your own break-even ACOS with the free calculator
Go deeper
The glossary gives you the one-line answer. The Amazon PPC Clarity Guide explains why it matters and what to do about it.