On Amazon the numbers come from many places: sales, listings, advertising, refunds, inventory. The risk is not a lack of data but looking at it in pieces. A useful Amazon Seller Central dashboard does not copy everything the platform shows. It keeps a few things in view for each of five areas and says, for each one, when to step in. This guide explains which ones, with decision rules, a worked example and an honest note on how to build a single view today.
The five areas to keep in view
An Amazon seller looks at five areas: sales and orders, products and listings, advertising, refunds and quality, account and inventory. They are connected. If advertising goes up and sales do not, you look at the listing. If a product is running out, advertising on it is wasted money. If refunds rise, the listing and the account both feel it. A useful dashboard puts the five areas in the same view, so the links show.
An example with made-up numbers, to show why they belong together. A seller has total sales steady at €50,000 for two months in a row. It looks like a quiet period. But advertising spend went from €5,000 to €6,500: the total did not move, yet something got worse. You only see it by reading advertising and total sales together, with two indicators explained below; the full calculation is further down, in the worked example.
What to monitor by area, with decision rules
Sales and orders
Sales, orders and average order value, against the previous period and the same period last year. Rule: if sales are steady but orders fall and average order value rises, check whether the product mix changed or a low-priced item dropped out of the offer. Always separate sales from advertising from organic sales: together they make the total.
Products and listings
For each main product: sales, share of the total and how the listing is doing (price, images, description, availability). Rule: if one product produces most of the sales, that dependence is a risk to review every month. If a product's sales fall while advertising is unchanged, check price and availability against competitors first, then the listing.
Advertising: ACOS and TACoS
Two indicators, to be read together. ACOS is advertising spend divided by the sales generated by advertising. TACoS is advertising spend divided by total sales, organic ones included. With €5,000 of spend and €20,000 of advertising sales, ACOS is 25%. With the same spend and €50,000 of total sales, TACoS is 10%.
Why do you need both? ACOS tells you what advertising costs against what it credits to itself. TACoS tells you how much it weighs on the whole store. A TACoS that rises while total sales stay flat can mean advertising is taking the place of sales that used to arrive on their own. A TACoS that falls while total sales grow is usually the healthiest signal: organic sales are growing faster than spend. Rule: do not judge a campaign by ACOS alone, and do not cut spend just because TACoS is high without looking at total sales.
Refunds and quality
Refunds and returns by product, not as a store-wide average, plus customer ratings and complaints. Rule: if refunds concentrate on a single item, the cause is almost always in the listing (wrong expectations, sizing, description) or the product; if they rise everywhere, look at delivery and packaging. A best seller with lots of returns is not a best seller.
Account and inventory
Account health indicators and platform notices, plus days of inventory cover. Days of cover are calculated like this: stock on hand divided by average daily sales. With 600 units and 20 sales a day, cover is 30 days. If replenishment takes 35 days, there is a five-day stockout risk. Rule: when cover drops below replenishment time plus a margin, reorder or reduce advertising on that product, because paying to drive traffic to an item about to run out is wasted spend, and a stockout can also cost the ranking the listing had earned.
A worked example: steady sales, rising TACoS
Back to the seller (made-up numbers). Last month: total sales €50,000, advertising sales €20,000, spend €5,000. This month: total sales €50,000, advertising sales €22,000, spend €6,500.
| Indicator | Last month | This month |
|---|---|---|
| Total sales | €50,000 | €50,000 |
| Advertising sales | €20,000 | €22,000 |
| Organic sales (total − advertising) | €30,000 | €28,000 |
| Advertising spend | €5,000 | €6,500 |
| ACOS (spend ÷ advertising sales) | 25.0% | 29.5% |
| TACoS (spend ÷ total sales) | 10.0% | 13.0% |
Looking only at total sales, nothing changed. TACoS rose three points, from 10% to 13%, and says the store is paying more to sell the same amount. The rest of the table explains why: spend grew by €1,500 and advertising sales by €2,000, but organic sales fell by €2,000. In practice the extra spend bought sales that used to arrive on their own.
That does not yet name the cause. Organic ranking may have slipped, a competitor may have cut its price, a listing may have been unavailable for a few days. This is the moment to open the table below, not to cut or raise spend at random.
Signal, likely cause, check
These are hypotheses to verify, not verdicts.
| Signal | What it may mean | What to check |
|---|---|---|
| Total sales steady, TACoS rising | Advertising is replacing organic sales, or competition costs more | Organic sales by product, price against competitors, keywords with rising cost |
| ACOS falling, total sales falling | Spend was cut and volume was lost | Which campaigns were reduced, and the organic sales tied to them |
| One product's sales falling, advertising unchanged | Price, availability or listing less competitive | Price and availability over recent days, images and description |
| Refunds rising on a single item | Quality, sizing or description problem | Return reasons, comparison with the description, production batch |
| Inventory cover below replenishment time | Stockout risk | Inbound orders, supplier lead times, ad spend on that product |
| Account notice or falling health indicators | A platform rule not met or too many service issues | The notice detail, the products involved, recent complaints |
Typical mistakes
- Looking only at ACOS. A campaign with a low ACOS can still pull organic sales away. TACoS shows it.
- Total sales without the advertising and organic split. A steady total can hide two opposite movements.
- Comparing uneven periods. A period with a promotion or strong seasonality is not comparable with a normal one. The useful reference is your own average over recent weeks, not a universal threshold.
- Ignoring inventory in advertising. Pushing a product with little stock is wasted spend.
- A store-wide average for refunds. It hides the problem product.
If you manage several accounts or work for several brands
Agencies and anyone looking after several brands have an extra problem: each account has its own definitions, campaigns and rhythms, and reporting turns into assembly work. You need the same five areas, with the same definitions of ACOS and TACoS, in a view that compares accounts and flags which one needs attention. It helps to write the definitions down once for everyone and use the same structure for every brand, so on Monday you read the exceptions instead of rebuilding sheets.
Where Opalca View fits
Opalca View is a set of ready-to-use dashboards for sales, products and customers, with automatic weekly and monthly reports. The connector that is live today is Shopify. Amazon Seller Central and Vendor Central are among the connectors on the way, and you cannot connect them yet: we cannot promise a date. Ask Opalca, the feature for asking your data questions in plain language, is included in the Growth and Enterprise plans and works on your store's Shopify data: it does not know your Amazon data or your advertising spend.
If you need an Amazon dashboard now, the route is to assess a custom project with Opalca Lab, which works on data source integration, API connectors and custom dashboards. One example is Turnover, an agency specialized in selling on Amazon, for which we built custom Amazon reporting dashboards. There is no standard price list: each project is assessed based on the sources and the questions. If your case is simple, a well-structured spreadsheet built around the five areas in this guide may be enough to start.
Want to find out whether you need a custom project? Talk to us. For other questions you can contact us.
Keep reading
- Ecommerce KPIs: the 10 metrics that matter and how to read them
- Data integration: what you need before building a dashboard
Frequently asked questions
What is the difference between ACOS and TACoS?
ACOS is advertising spend divided by sales from advertising. TACoS is advertising spend divided by total sales. The first judges advertising on its own, the second its weight on the whole store.
What is a good ACOS or TACoS?
There is no value that fits everyone: it depends on margins, products and stage. The useful reference is your own average over recent weeks and the margin left after spend.
How often should they be checked?
Sales, advertising and inventory every week. Refunds by product and dependence on main products make more sense monthly.
Does Opalca View connect to Amazon?
Not yet. Amazon is among the connectors on the way, while the one that is live today is Shopify. For an Amazon dashboard now, a custom project with Opalca Lab can be assessed.
Do I need a dashboard if I have a single account?
Not always. With few products and one account, a well-structured spreadsheet can be enough. A dedicated view becomes useful when products grow, there is more than one source, or assembling reports starts to weigh on you.