Clear definitions of the metrics and concepts that matter when auditing Amazon advertising performance — from ACOS and TACoS to inventory reconciliation and FBA reimbursements.
Advertising Cost of Sales. ACOS is calculated as ad spend divided by ad-attributed sales. It tells you how much you spend in ads to generate one unit of revenue.
Why it matters: Core profitability metric for Amazon ads. Used to set bid and budget guardrails. See also TACoS and TACoS calculator.
Total Advertising Cost of Sales. TACoS is calculated as ad spend divided by total store sales (ad-attributed + organic). It reflects how dependent your revenue is on paid media.
Why it matters: TACoS trend is a leading indicator of whether advertising is building organic momentum or just buying revenue.
Return on Ad Spend. ROAS is calculated as ad-attributed sales divided by ad spend. It is the inverse of ACOS and is often expressed as a "3.5x" style multiple.
Why it matters: Easy for leadership teams to interpret when comparing channels and campaigns side-by-side.
Cost Per Click. The average amount you pay for a single click on your ad. Calculated as total spend divided by total clicks.
Why it matters: Rising CPC with flat conversion usually signals increasing competition or poor query-to-product fit.
Click-Through Rate. The percentage of impressions that turn into clicks. Calculated as clicks divided by impressions.
Why it matters: Indicates ad relevance and creative strength. Low CTR suggests weak targeting or uncompetitive creative.
Conversion Rate. The percentage of clicks that result in an order. On Amazon, CVR is usually calculated as orders divided by clicks.
Why it matters: Sensitive to pricing, reviews, content, and competition. High CVR supports higher bids.
Ad CVR uses ad clicks as the denominator, while Session CVR (from Business Reports) uses total sessions. The gap between the two highlights how efficiently paid traffic converts vs all traffic.
Why it matters: Large gaps can indicate targeting issues or misalignment between ad creative and product page.
Ad spend that generates clicks but no attributed orders over the attribution window. Often sits in broad or auto campaigns with weak negative keyword coverage.
Why it matters: First place to look when running a profit leakage audit. See Zero-Conversion Keywords.
Search terms or targets that have generated clicks but zero orders over a meaningful sample size. Often symptomatic of poor query-to-product fit or low product page conversion.
Why it matters: Removing or negating these keywords usually yields instant ACOS improvement.
Amazon report listing the actual customer search queries that triggered your ads, along with clicks, spend, and conversions.
Why it matters: Primary source for keyword mining and waste identification in any audit.
Report that shows performance at the target level (keywords, ASINs, categories) rather than the raw search term level.
Why it matters: Helps identify underperforming targets even when individual search terms are noisy.
SP Advertised Product Report summarises performance at the advertised ASIN-level. Each row represents an ASIN within a campaign.
Why it matters: Core input for the audit engine's canonical aggregation layer.
Amazon Business Reports provide view and sales metrics at the ASIN level, including sessions, page views, and unit session percentage.
Why it matters: Used to reconcile organic vs ad-driven sales and validate ad attribution.
Sales that occur without a direct ad click in the attribution window. Estimated as total store sales minus ad-attributed sales.
Why it matters: Organic sales share is the real measure of brand strength on Amazon.
Revenue credited to an ad click within the attribution window (usually 7 or 14 days depending on placement and ad type).
Why it matters: Core input for ACOS and ROAS calculations.
Sales attributed to an ad where the ordered ASIN is different from the advertised ASIN. Indicates basket-building and cross-selling effects.
Why it matters: Important for brands with strong catalogues where ads drive ecosystem rather than single SKU performance.
The highest ACOS at which you do not lose money on a sale. Calculated using product margin after all fees and cost of goods.
Why it matters: Essential for setting ACOS targets by SKU and avoiding silent margin erosion.
The percentage of available impressions your ads received for a given set of queries or placements. Often available in Sponsored Brands and Display reporting.
Why it matters: Indicates headroom for scaling spend on winning segments.
The percentage of impressions your ads receive in the premium top-of-search placement vs other placements.
Why it matters: Critical for high-intent queries where top positions capture the majority of clicks.
Keyword match type where the customer search term must closely match your keyword to trigger an ad. Provides tight control over queries.
Why it matters: Backbone of mature campaign structures and hero keyword defence.
Match type that allows your ad to show on a wide variety of related searches, including synonyms and reordered terms.
Why it matters: Powerful for discovery, but dangerous without strong negative keyword hygiene.
Match type where the customer search term must contain your keyword phrase in the same order, with words allowed before or after.
Why it matters: Balance between control and discovery when building out mid-funnel coverage.
Sponsored Products campaign type where Amazon automatically matches your ads to relevant search terms and products using its own signals.
Why it matters: Great for discovery, but must be paired with regular negative keyword pruning to avoid waste.
In Targeting Reports, a dash ("-") often represents automatic targeting rather than a specific keyword match type.
Why it matters: Helps distinguish between manual and auto traffic when auditing performance.
Process of comparing the units you shipped to Amazon with the units Amazon confirms receiving and holding in stock.
Why it matters: Identifies lost, damaged, or missing units eligible for reimbursement.
FBA inventory that goes missing or is damaged within Amazon's fulfilment network. Typically surfaced through inventory adjustment and reconciliation reports.
Why it matters: One of the most common sources of reimbursement in profit leakage audits.
Difference between what you sent to Amazon and what Amazon recorded as received for a shipment or FBA inbound.
Why it matters: Each discrepancy may represent units you can reclaim through support cases.
Weight used by Amazon to calculate fulfilment and storage fees when a product's size, not just scale weight, drives cost to ship.
Why it matters: Dimensional weight changes can quietly increase fees and erode margin.
Fee Amazon retains when a customer returns a product, typically 20% of the original referral fee.
Why it matters: Meaningful drag on profitability in high return-rate categories and must be accounted for in margin models.
Credit Amazon issues when it confirms responsibility for lost or damaged inventory, shipment discrepancies, or fee overcharges.
Why it matters: Recovering missed reimbursements is a direct profit lift with no incremental ad spend.
Financial report that itemises charges, fees, refunds, and payouts at the transaction level.
Why it matters: Backbone for any deep profit leakage or fee accuracy audit.
Percentage of page views where your offer held the Buy Box for a given ASIN. Reported in Business Reports or Brand Analytics.
Why it matters: Low Buy Box percentage limits the ceiling of paid and organic sales.
Sessions count unique visits over a period; page views count every time a page is loaded, including repeat views in a single session.
Why it matters: Understanding the difference helps interpret Business Report metrics correctly.
Business Report metric calculated as units ordered divided by sessions. Often used as a proxy for conversion rate on Amazon.
Why it matters: Key signal for listing health and price competitiveness.
Total sales derived from ordered units for a given ASIN or grouping, excluding cancellations and returns until they are processed.
Why it matters: Base figure for many performance and profitability calculations.
Common attribution window for Sponsored Products, counting orders that occur within seven days of an ad click.
Why it matters: Misunderstanding attribution windows leads to under- or over-crediting campaigns.
Keyword and product-targeted ads that promote individual listings within Amazon search results and product pages.
Why it matters: Foundation of most Amazon advertising programmes and the primary data source for the audit engine.
Advertising format that promotes a brand and a collection of products, often appearing as banner placements at the top of search results.
Why it matters: Useful for branded search defence and mid-funnel category building.
Display-style ads that can appear on and off Amazon, targeting audiences based on shopping behaviour and product views.
Why it matters: Extends reach beyond search results and supports remarketing strategies.
Advertising run on retailer-owned media networks such as Amazon, Walmart Connect, or other marketplace platforms.
Why it matters: Increasingly central to modern shopper marketing strategies and budget allocation.
The directional change of TACoS over time. A falling TACoS with stable revenue implies organic growth; a rising TACoS may signal over-reliance on ads.
Why it matters: One of the clearest indicators of whether your strategy is compounding or stalling.
Selling Partner API. Amazon's official API for programmatic access to reports, orders, inventory, and advertising data.
Why it matters: Underpins automated reporting, audits, and custom tooling such as the audit engine.
The way campaigns, ad groups, and keywords are organised to reflect goals, product groupings, and budget constraints.
Why it matters: Strong structures make scaling, testing, and auditing dramatically easier.
Container within a campaign that holds a set of ads and targets. Often used to group closely related products or themes.
Why it matters: Determines how bids and budgets are applied to clusters of queries and products.
Amazon's way of grouping campaigns for budgeting and reporting purposes. Portfolios can be used to roll up spend by brand, region, or objective.
Why it matters: Helpful for structuring budgets across large multi-brand or multi-marketplace accounts.
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