ROAS measures ad revenue divided by ad spend. ACoS is ad spend divided by ad revenue. TACOS compares total ad spend with total marketplace revenue, so it shows whether paid growth is improving the whole account.
E-Commerce Glossary referenceDefinitions, decision points and weekly checkpoints.
18%CM2+37%DRRLowRisk
AmazonPractical Guide
What sellers should know.
This page is written for ecommerce teams that need clear decisions, not surface-level definitions.
CM1 starts after COGS and marketplace fees. CM2 adds ads, returns, shipping and payment impact. CM3 adds overhead allocation, making it useful for brand-level profitability decisions.
DRR is daily run rate. Stock cover tells how many days inventory can support expected sales. Fill rate shows how much quick commerce demand is served without store-level gaps.
Use these metrics together. Revenue without CM2, ads without TACOS, and inventory without stock cover can all hide real business risk.
Action checklist
Use this as a quick review before changing budgets, inventory, pricing or channel strategy.
✓Map every metric to a weekly action
✓Separate revenue metrics from profit metrics
✓Review SKU-level numbers, not only account totals
✓Use one source of truth for reporting
When to review
Review this weekly when revenue, ad spend, stock, returns or marketplace fees are changing.
Common mistake
The biggest mistake is reading this metric alone without checking contribution, inventory and customer behaviour.
Apex support
Apex connects this with catalog, ads, analytics, marketplace operations and profitability planning.
Next step
Use a related calculator, then speak with Apex for a practical growth audit.
Apply This
Turn This Into ActionNeed help applying this to your ecommerce business?
Apex can convert the guide into a SKU, platform, ads, inventory or profitability action plan.
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