Practice case: shop revenue grows 25% in eight weeks—why does profit fall?

One simulated shop, two four-week periods

This scenario practices report interpretation, not a real shop's results. Assume the shop sells the same product group over eight weeks. The first four have 800 completed orders and VND 240 million collected revenue; the next four have 1,000 completed orders and VND 300 million. Average order value is VND 300,000 in both.

From orders and revenue alone, the later campaign seems successful: both grow 25%. Operators must read three more lines: variable costs before advertising, advertising and fixed costs.

What does the period comparison show?

Weeks 1–4: revenue VND 240 million, variable costs before advertising VND 168 million, contribution before advertising VND 72 million, advertising VND 48 million and contribution after advertising VND 24 million. Subtracting VND 20 million fixed costs yields an estimated positive operating result of VND 4 million.

Weeks 5–8: revenue VND 300 million, variable costs before advertising VND 220 million, contribution before advertising VND 80 million, advertising VND 65 million and contribution after advertising VND 15 million. Subtracting VND 22 million fixed costs yields an estimated negative operating result of VND 7 million.

Each first-period order contributes VND 90,000 before advertising and VND 30,000 after. The later figures are VND 80,000 and VND 15,000. Advertising cost per completed order rises from VND 60,000 to VND 65,000. This per-order contraction worsens the total result despite more orders.

Three hypotheses to check before concluding

The shop may fund more vouchers, sell more low-margin products or incur extra delivery and return costs. These could explain variable costs rising from VND 210,000 to VND 220,000 per order. Split reports by SKU, program and completed orders to see what actually changed.

Advertising may also expand into harder-to-convert customers, content may draw views without completed orders, or attribution may incorrectly assign existing-customer orders to the campaign. Do not label a channel ineffective from two aggregated lines.

The VND 2 million fixed-cost increase explains part of the difference, but contribution after advertising already fell VND 9 million. Prioritize per-order economics before cutting every shared cost.

A small two-week experiment

Choose a product group with enough orders to observe, keep measurement unchanged, then test reducing vouchers or adjusting bundles. Track collected revenue, variable costs, advertising per completed order and total contribution. Changing many things at once obscures what caused the result.

Use the order-profit calculator to test scenarios before launch. Compare actual data within the same channel and customer group afterward. If new customers may repurchase, set a suitable tracking horizon and compare CAC with accumulated contribution, without adding unobserved future revenue.

Choose the next article by your bottleneck

If contribution before advertising is low, revisit discounting or AOV. If advertising per completed order rises, examine break-even ROAS and CAC/LTV. If orders look good but money arrives slowly, read about profit versus cash flow.

The Profitable Selling roadmap helps select the right branch. When each branch answers a specific question, operators can move from a report to next week's action rather than just inspect the final number.

Suggested actions