The typical account we audit has somewhere between fifteen and thirty percent of advertising spend going to search terms that have never produced a sale. Nobody decided this. It accumulated.
Set the threshold first
Decide what counts as waste before opening the report. A reasonable starting point is: spend exceeding two to three times the product's price with zero conversions, over a lookback window of at least sixty days.
Set this by price band. A $12 accessory and a $180 piece of equipment need very different thresholds, and applying one rule to both will either negate future winners or leave losers running.
Pull the data properly
Use a search term report covering at least twelve months, not the default thirty or sixty days. Seasonal terms look like waste in the off season and are worth keeping. Classify every term against the threshold before making any changes.
Negate carefully
- Apply negations at the ad group level where the term is irrelevant to those specific products, and at campaign level only where it is irrelevant to the whole campaign.
- Use negative exact for specific terms and negative phrase only when you are confident about the whole pattern.
- Work in weekly batches. One sweep makes the before-and-after impossible to read and hard to reverse.
- Keep a log of every negation and its reason. You will want it in three months.
Redeploy immediately
The point is not to spend less. It is to spend the same amount better. Move each week's reclaimed budget into proven exact-match terms, higher placement multipliers where placement data supports it, or SKUs with margin headroom.
Hold total budget flat through the exercise. That way the result is unambiguous: same spend, more sales, and an argument you can take to whoever controls the budget.
Then make it routine
A one-off audit gets you back to where you should have been. A weekly harvest-and-negate routine, with the same written thresholds, keeps you there. The routine is the deliverable; the audit is just the catch-up.