A repeatable pass over search-term reports that usually reclaims 8–12% of wasted spend without touching bids.
Why 14 Days is the Sweet Spot
Audit too frequently (like daily), and you overreact to statistical noise, cutting search terms that would have converted on click 6. Audit too rarely (like monthly), and wasteful search terms rack up hundreds of dollars in unconvertible spend.
A rolling 14-day audit captures sufficient click density while allowing you to react before ad spend leaks significantly.
For the overarching mathematical bidding system that accompanies negative harvesting, consult: The Complete Amazon PPC Guide for 2026 (Chapter 10: Negative Keywords).
The 3-Step Negative Filtering Framework
Step 1: Zero-order filter. Filter search terms with >10 clicks and 0 orders. Add as negative exact at the campaign level.
Step 2: Irrelevant intent harvest. Look for brand names of products you do not sell, accessory terms for different device models, and terms like "free", "cheap", or "repair". Add these as negative phrase.
Step 3: High-ACoS cull. Identify queries where ACoS exceeds 2x your break-even threshold with at least 15 clicks.
Pair this negative keyword pass with regular bid calibrations detailed in our pillar manual: The Complete Amazon PPC Guide for 2026 (Chapter 11: Bid Optimization).
Frequently Asked Questions
Founder & Head of Strategy at Fatten Media. We help 7- and 8-figure Amazon brands scale profitably through precision PPC and listing architecture.