ACOS vs TACOS on Amazon

ACOS measures ad spend relative to ad-attributed sales. TACOS measures ad spend relative to total sales, including organic revenue. Use ACOS to examine advertising efficiency and TACOS to understand how much of a marketplace's revenue is spent on advertising. Neither is a complete profit metric or proof that advertising caused a sale.

Calculate both from the same window

For a fictional US account, assume $1,000 advertising spend, $4,000 ad-attributed sales and $10,000 total sales, all in USD for the same dates and scope.

ACOS = $1,000 / $4,000 × 100 = 25%
TACOS = $1,000 / $10,000 × 100 = 10%
ROAS = $4,000 / $1,000 = 4

Do not add ad-attributed sales to a total-sales figure that already includes those sales. That counts revenue twice and makes TACOS look artificially low. If the denominator is zero, the percentage is undefined. If total sales is missing, show that absence instead of relabelling ACOS as TACOS.

What ACOS can and cannot tell you

ACOS describes the efficiency of sales credited to advertising under the report's attribution rules. It is useful for reviewing a keyword, target or campaign against a chosen target when the evidence is sufficient.

It does not subtract product cost, fulfillment fees, returns or other expenses. A 25% ACOS can be acceptable for a product with 40% contribution before ads and loss-making for one with 20%. Check Break-even ACOS and your business goal before calling an ACOS good or bad.

Attribution differs from causation. Some ad-attributed purchases might have happened without the ad, while advertising can affect later discovery or demand that a report does not credit. Do not assume either direction from ACOS alone.

What a change in TACOS means

Falling TACOS with flat spend: total sales increased relative to ad spend. That can be consistent with stronger organic demand, but pricing, promotions, stock, seasonality and other channels can contribute. The metric alone does not identify the cause.

Rising TACOS with flat ACOS: total revenue is not keeping pace with spend in the same way as ad-attributed revenue. Examine the component figures and attribution timing before concluding organic sales are falling.

Flat TACOS with higher spend: total sales rose proportionally to spend. This is not proof that the added advertising caused all the additional revenue or that the margin is acceptable.

Very low TACOS: the business uses a small share of revenue for ads. It may be efficient, have strong non-ad demand, or have room to test more advertising. The percentage alone cannot determine which.

Supply the right total-sales data

Advertising reports contain attributed revenue, not the complete seller-sales denominator. Total sales must come from an appropriate seller report, a supplied value or a reliable seller-data integration. The important distinction is verified versus missing input, not whether a number was entered manually.

Match dates, marketplace, currency and the scope of advertising spend. If a figure includes spend across multiple ad formats, its label should make that clear. Check how returns, tax and other report differences are handled before comparing systems.

AutoPPC computes true TACOS when matching seller total-sales input is supplied. An automated seller-sales connection is a different capability from accepting and using that input.

Keep US and Canada readable separately

Never add USD and CAD amounts without conversion. AutoPPC keeps the marketplaces separate so that each market's spend, sales and goals remain understandable.

A consolidated ratio can be mathematically valid after consistent currency conversion, but it can hide different economics and performance. Growth in a lower-TACOS market can improve the combined ratio even if neither market becomes more efficient. Keep market-level results alongside any deliberate consolidation.

Choose a goal and a measurement period

Start with product contribution, cash constraints and the purpose of the advertising. A mature product, a launch and a stock-clearance campaign can justify different goals. State what you are willing to spend and when you will revisit that choice.

Use settled, comparable windows and record price, stock, promotion and campaign changes. There is no universal six-week or eight-week interval that proves an organic effect. Attribution maturity and the time needed to observe demand depend on the account and question.

For causal claims, a simple before-and-after comparison is weak evidence. Where practical, use a properly designed experiment or a credible comparison group; otherwise describe the change as an observation and name competing explanations.

What AutoPPC does with this

AutoPPC keeps TACOS marketplace- and currency-specific and requires total-sales input. Its individual Sponsored Products bid proposals use saved ACOS targets and deterministic rules; TACOS provides business-level reporting context.

Use the audit checklist to connect the metrics to a review, and the worked audit example to distinguish an observed result from a proposed change.