Amazon PPC Guide
A practical playbook to lower advertising cost of sale — from search term cleanup to bid optimization.
ACOS = (Ad Spend ÷ Ad Sales) × 100
ACOS is Amazon's advertising cost of sale — not the math function arccos. Use our Amazon ACOS calculator to model spend and savings.
If your ACOS is too high, you are either paying for the wrong clicks or your listing is not converting the traffic you earn. The steps below address both — in the order most sellers see the fastest impact.
Export 60 days of search terms. Flag anything with spend but no sales, and terms that do not match your product. These become negative keyword candidates immediately.
Use phrase and exact negatives for irrelevant queries. BidBoost automates waste detection and surfaces plain-English negative keyword recommendations from your live data.
Promote proven search terms from broad to phrase or exact. Stop paying for discovery on terms you already know convert.
Lower bids on low-converting placements. Raise bids only where ACOS is at or below target. Inventory-aware rules prevent spend on out-of-stock ASINs.
ACOS is partly an ads problem and partly a listing problem. Better images, titles, and reviews improve conversion rate, which lowers ACOS at the same bid.
Pick a target based on margin, then review campaign-level ACOS every week. Pause or restructure campaigns that stay above target for 14+ days.