The rule
Spend up to roughly two to three times your break-even CPA with no conversion, and the thing has answered you. With conversions but below 70% of break-even ROAS over a meaningful window, it is draining.
Before cutting, check three things
- Is it tracked correctly? A campaign with a broken tag looks identical to one that does not convert.
- Is the product disapproved or out of stock?
- Are the search terms right, or has it drifted?
Then cut properly
Pause, do not delete — the history is worth keeping. And move the budget somewhere deliberate rather than letting it disperse.