Same Product, 4× the Inquiry Cost: It's the Ad Solution, Not the Product
TL;DR
The same product, listed in different marketplace ad solutions, can cost 4× more per inquiry. Weekly ad records for three key products in one store show the same product ranging from ¥17 to ¥78 — and the ordering is dictated by the solution: the merchant growth program is the most expensive for all three products, and switching solutions moves one product's cost by up to 4×. Three rules fall out: grade products on the blended number, grade solutions on same-product same-period comparisons, and never compare solution numbers across non-overlapping time windows.
The situation: the product you're about to pause was wronged by its channel
Monday review: a product's inquiry cost in your flagship solution looks terrible, and you're considering pausing it. Hold on — the real ledgers of three key products in one industrial-goods store (anonymized) show the same product ranging from ¥20 to ¥78 depending on the channel it enters through. Same product, same page, same price. This reconciliation came out of a weekly-ad-ledger audit while building AI Operations.
Why: for the same product, the solution sets the price
Line up the weekly records of all ad solutions for three key products. Full-history view first (inquiry cost = cumulative spend ÷ cumulative inquiries):
| Ad solution | Delivery window | Product A | Product B | Product C |
|---|---|---|---|---|
| Whole-store promotion | 2024-04 ~ 2026-06 (68–116 wks) | ¥30 | ¥37 | ¥26 |
| Site-wide, shop-boosting | 2025-11 ~ 2026-06 (31–33 wks) | ¥25 | ¥25 | ¥17 |
| Merchant growth program | since 2026-06-29 (8 wks) | ¥77 | ¥78 | ¥49 |
| New-customer crowd | same period (8 wks) | ¥50 | ¥20 | ¥29 |
| Cross-border express | same period (7–8 wks) | ¥42 | ¥22 | ¥28 |
Three layers of structure, each more useful than the last:
1. Full history: priciest vs cheapest is 4×+ — ¥78 against ¥17.
2. The ordering is dictated by the solution. The "Merchant growth program" is the most expensive for all three products (¥49–78) — three completely different products, uniformly expensive in this one solution. The dominant factor is the solution (what traffic it buys), not the product (what it sells).
3. Within the same period: 1.8–3.9×. The last three solutions share one time window (8 weeks from 2026-06-29), so their comparison is clean: 1.8× for Product A, 3.9× for Product B, 1.8× for Product C.
(Technical note: the first two solutions' data ends on 2026-06-29 and the last three start that very day — the windows don't overlap. So "old ¥25 vs new ¥77" mixes two factors: solution differences and market seasonality; concluding directly misleads. Statistically this is kin to Simpson's paradox — conclusions consistent per layer can flip once merged. Every "n×" claim in this article comes from the same-period window only.)
One counter-intuitive detail: the "Merchant growth program" isn't cold-start expensive — it keeps getting more expensive. Across its 8 weeks, inquiry cost climbed from ¥26 to ¥107. That retires the "give the new solution time" excuse; money dictated by traffic structure does not arrive with waiting.
What it's worth: two ledgers
The mis-kill ledger. Product B runs at ¥20 per inquiry in "New-customer crowd," about a dozen-plus inquiries a month. Pause the product because it shows ¥78 in the growth program, and what you discard is not a bad product — it's a cheap channel still delivering steadily.
The true-cost ledger. Which of Product B's five numbers (¥37 / ¥25 / ¥78 / ¥20 / ¥22) is real? All of them, and none. Its actual acquisition cost is the blended one: ¥32,265 total spend ÷ 911 inquiries = ¥35. A single-solution number can overstate or understate a product; only the blend is the product's real price tag — and the stable anchor for budget allocation.
Disciplines for operators
- Grade products on the blend: total spend ÷ total inquiries. Per-solution numbers answer "is this channel expensive," never "is this product good."
- Grade solutions on same-product, same-period comparisons: fix a basket of products and a time window; only then does the ordering mean anything.
- Never compare across non-overlapping windows: solution handover periods are the danger zone — an old solution's historical cost is not the new one's ruler.
- A persistently worsening solution isn't worth waiting for: cut budget after 4+ weeks of climbing costs; make keep-or-stop calls with the settlement discipline from Is 16 Days Enough for Marketplace Ad Data? and the full pre-pause checklist in Five checks before you pause.
One line to remember
Products get the blend; solutions get the same period. Before comparing costs across windows, align the time.
FAQ
The same product shows very different inquiry costs across ad solutions — is that normal?
Yes. Across three key products we measured ¥17 to ¥78 for the same product, and the ranking followed the solution, not the product — each solution buys different traffic.
Which inquiry cost should I use to judge a product?
The blended one: total spend across all solutions ÷ total inquiries. A single-solution number only says what that channel pays for this traffic — it cannot grade the product.
Can I compare costs across different ad solutions directly?
Only within overlapping time windows. When old and new solutions don't share dates, the gap mixes solution differences with market seasonality — comparing directly misleads.
That "line up every channel for the same product" reconciliation is built into AI Operations — LLM-powered analysis that automatically surfaces market trends, user behavior, and sales data to drive strategy. Every product's real acquisition cost deserves to be computed once, fully.
CCLEE
Independent developer, 24 years in e-commerce, focused on grounding AI in real business scenarios.
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