Why audit Amazon Ads at all
Seller Central moves fast. Campaign performance shifts weekly. If you don't audit regularly, dead keywords keep burning cash, inflated CPCs go unnoticed, and ACoS creeps past profitability before you catch it.
Run this audit every two weeks or, at minimum, quarterly. The goal: cut wasted spend, find better keywords, and know exactly what's working before competitors move faster.
CPC: Know your auction position
Cost per click tells you two things: what you're actually paying per impression, and how competitive your category is.
Pull your CPC from Seller Central Advertising Reports. Compare it to category average. If your CPC is 50% higher than average, either your bid is too aggressive or your ad relevance is low (Quality Score equivalent). Cut the bid, tighten keyword-to-product match, or move budget to better-performing campaigns.
High CPC doesn't always mean high ACoS—but it's the first lever to check.
ACoS: The only number that matters to margins
Advertising Cost of Sales = ad spend ÷ revenue from those ads. If you spend $100 and make $400, ACoS is 25%. Your target depends on product margin, category, and growth phase.
Check ACoS weekly. Trending up? Keywords are losing relevance or competition is higher. Trending down? You've found something—scale it before others catch on.
Use Amazon's Advertising Reports or sync data to a spreadsheet. Track by campaign, keyword, and product. Some sellers run aggressive ACoS (80-100%) to launch new products, then tighten it once they hit review velocity and conversion rate improves.
KPIs: Spot problems early
Key Performance Indicators vary by account, but track these:
- Impression share: Dropping impressions mean keywords are losing rank or new competitors entered. Investigate top keywords first.
- Click-through rate: Below 0.5%? Ad copy or image isn't resonating. Test new creative or recheck keyword-to-product relevance.
- Conversion rate: Audience clicking but not buying points to pricing, shipping time, or review count.
- Return on ad spend (ROAS): Revenue ÷ ad spend. If ROAS drops, ACoS is climbing and margins compress.
Compare your KPIs to Amazon category benchmarks. This tells you if underperformance is category-wide (macro) or account-specific (fixable now).
Keywords: Prune, don't dump
Amazon caps impression-sharing at ~25–50 keywords per ad group. Above that, Amazon deprioritizes all of them. Add over-stuffed ad groups? You get no impressions.
Instead, create tight single-keyword or 3–5 keyword ad groups. Match intent precisely.
Flag anomalies: keyword with 1,000 impressions but zero clicks means low relevance—add it to negative keywords. A keyword converting at 8% ACOS but getting few clicks? Increase bid. Keyword converting at 40%+ ACOS? Cut it or move it to a lower-bid campaign.
Run this audit, then decide
Every two weeks, export your data. Spot three changes: one CPC adjustment, one keyword kill, one bid increase on a winner. Ship it. Measure for two weeks. Repeat.
If audit work consumes time better spent on product, operations, or pricing, bring in a partner. An AI-native growth agency can audit, optimize, and report weekly while you run the business.