How it works
Your break-even CPA is the single most important number in paid e-commerce, and most people never calculate it. It is simply your selling price minus your product cost minus payment fees. That leftover is the absolute maximum you can spend to acquire one customer before you start losing money.
Example from my pricing playbook: a $44 product with $18 COGS and $2 in fees leaves a $24 break-even CPA. That is $24 of room to buy each customer. The same product priced at $29 leaves barely $9, which on most US products is fantasy. Price for ad room first, then scale.
This is the ceiling, not the target. To actually profit, your real cost per acquisition has to come in below this number. Use the profit checker to see what you keep at a given CPA.