Gross Margin

gross margin · gross profit margin · gross profit · margin · gross margin percentage · cogs margin

Definition

Gross margin is the share of revenue that remains after the cost of goods sold is deducted; it shows the base profitability of sales before operating expenses.

The formula and its components

Gross Margin (%) = (Revenue − COGS) / Revenue × 100%

Gross Profit ($) = Revenue − COGS

COGS (cost of goods sold) in e-commerce covers:
– The purchase price of the item from the supplier
– Shipping from the supplier to the warehouse
– Packaging, where it forms part of the unit cost

COGS excludes marketing spend, salaries, warehouse rent and payment processing fees — all of
those are operating expenses that sit below gross profit in the P&L.

Typical values by vertical

Vertical	Gross margin
Grocery	10–25%
Electronics	5–15%
Fashion / apparel	40–60%
Beauty / cosmetics	50–70%
DIY / building materials	25–40%
Furniture	30–50%

That spread explains why “a 10% GMV lift” is worth something entirely different to a grocery
retailer than it is to a fashion retailer.

Gross margin and personalization

Calculate ROI the right way

The wrong calculation: personalization delivered +8% GMV → ROI = 8% of revenue / cost of platform.

The right calculation:

Real profit gain = +8% GMV × Gross Margin %

At $500M GMV and a 20% gross margin:
+8% GMV = +$40M of additional GMV
Gross profit gain = $40M × 20% = $8M

It is that $8M that gets set against the annual cost of the platform.

Margin mix improvement

Personalization affects not only the volume of sales but their composition. If the recommendation
engine surfaces high-margin products more often (private label, accessories, complementary
assortment), the average gross margin % across the basket rises.

Tip: when configuring merchandising rules in a recommendation engine, product margin can be
included as one of the sorting signals. It is a legitimate way to improve gross margin and keep
recommendations relevant at the same time — provided the quality of the selection does not degrade.

Gross margin in unit economics

The full e-commerce unit-economics chain:

GMV
  − Returns = Net Revenue
  − COGS = Gross Profit
  − Marketing, logistics, CS = Contribution Margin
  − Fixed costs = EBITDA

Gross margin is the second line of that chain. Every metric below it (contribution margin, EBITDA)
is smaller in percentage terms. Which is why any tool that increases revenue is assessed on its
contribution to gross profit, not to GMV.

Frequently asked questions

How is gross margin calculated?

Gross margin = (revenue − COGS) / revenue × 100%. COGS (cost of goods sold) is the cost of the products sold: purchase price, inbound logistics to the warehouse, packaging. It excludes marketing, salaries and rent — those are operating expenses (OpEx).

Why does gross margin matter when assessing personalization ROI?

A personalization platform costs X per year. It delivered +10% to GMV. But the real profit gain = +10% × gross margin %. At a 15% margin the profit gain is +1.5% of base revenue. That is what gets compared with the cost of the platform — not the GMV lift itself.

How does personalization affect gross margin rather than just GMV?

If personalization increases sales of high-margin products (private label, accessories, complementary items carrying an above-average mark-up), gross margin % rises even when total GMV stays flat. This is known as margin mix improvement.