ACOS
Advertising Cost of Sales — ad spend as a percentage of attributed revenue. The mirror of ROAS, and just as blind to cost.
Ad waste
Ad spend that did not pay back after fees, COGS, and fulfillment — the unprofitable share of a marketplace ad budget.
Attribution inflation
The ratio of GMV a platform credits to your ads to the GMV your ads actually caused. It is a multiplier on every ad target you set, and it cannot be read off any dashboard.
Attribution window
The period after a click or view in which a resulting order still counts as the ad’s. Change the window and the same campaign changes ROAS.
Bayesian inference
Estimating with a range instead of a single number, so a decision can account for how little it actually knows.
Break-even ROAS
The platform ROAS at which a campaign returns exactly what it costs. One divided by your contribution rate — the single number every ad target should be built on.
COGS
Cost of Goods Sold — the landed unit cost of getting a product into your hands. The number every margin calculation hinges on.
Contribution margin
Revenue minus every variable cost of selling one more unit — the profit each sale actually contributes after fees, ads, and fulfillment.
CPC and CPM
Cost per click and cost per thousand impressions — the two prices you pay in an ad auction, and the two ways a campaign gets expensive.
CVaR
Conditional Value at Risk — the average outcome in the worst cases. Not how often it goes wrong, but how bad it gets when it does.
GMV Max
Shopee’s automated campaign type — the platform takes targeting, bidding, and placement, and you keep only the budget and the ROAS target.
Incrementality
The sales an ad actually caused, as opposed to the sales it was credited with. Usually a much smaller number.
Low-margin SKU
A product whose contribution per unit is too thin to fund the attention it consumes — often a former bestseller nobody re-checked.
Marginal ROAS
The return on the next baht of ad spend, not the average across all of it. The number that decides whether to scale a campaign.
Marketplace fees
The platform’s cut on every order — commission, transaction, and seller-funded promotions. The largest hidden line item for most sellers.
POAS
Profit on ad spend — contribution earned divided by ad spend, where ROAS uses revenue. A POAS of 1.0 is break-even; a ROAS of 1.0 is a large loss.
Price elasticity
How much demand moves when price moves. The number that decides whether a discount buys volume or just gives away margin.
Probability of loss
How often a campaign has a losing day. A frequency, not an amount — and on sparse campaigns it measures the wrong thing.
Recommendation confidence
How often a proposed change beats doing nothing. A comparison against the status quo, not a score for the campaign.
Reorder point
The stock level that triggers a replenishment order — expected demand over the lead time, plus the safety buffer.
Safety stock
The buffer held against demand and lead-time variance. Priced by what a stockout costs you, not by a rule of thumb.
Stockout
Inventory hitting zero on a SKU customers want to buy. Lost revenue, wasted ad spend, and a ranking penalty that outlasts the restock.
Take rate
The share of gross merchandise value a marketplace keeps. The seller-side view of the platform’s business model.
Target ROAS
The revenue-per-ad-baht goal you hand an automated campaign. A gross-revenue instruction the platform will obey precisely, profitable or not.
Thompson Sampling
A way to keep learning about uncertain campaigns while still funding the proven ones — exploration without a fixed test budget.
True ROAS
Advertising return after platform fees, COGS, vouchers, and fulfillment — the profit-aware number platform dashboards rarely show.