marketplace ad spend ROAS comparison
Which Marketplace Should Get More Ad Spend? Why Revenue Alone Can't Answer That
Published: 2026-07-29
In short
When advertising across multiple marketplaces, it's tempting to increase ad spend on whichever marketplace has growing revenue. But without separating out how much of that growth is driven by advertising versus organic factors, you can end up pouring more ad spend into a marketplace where it's actually less effective. Because the advertising mechanics and billing models differ by marketplace, without a way to compare ad performance (ROAS) across marketplaces, ad-spend allocation tends to become a gut call.
Introduction: should ad spend just go to whichever marketplace is selling well?
When selling across multiple marketplaces, it's common to run ads on each one separately. When it's time to review budgets, the instinct is usually to put more ad spend behind whichever marketplace has the highest revenue. But revenue size and ad effectiveness don't necessarily move together. Some products or marketplaces sell well without any ad spend at all, while others only sell because of the advertising. If you allocate ad spend without distinguishing between these two cases, you can end up pouring more budget into a marketplace where it's actually less effective.
Each marketplace has a different advertising mechanism
Most marketplace platforms offer performance-based or pay-per-click advertising menus that boost a product's visibility in search results or featured placements. Rakuten has search-linked advertising options; Amazon has pay-per-click ads known as Sponsored Products. Yahoo! Shopping offers an advertising menu called the PR Option. ZOZOTOWN, on the other hand, differs based on the seller's format on the platform (consignment vs. self-managed merchandising, for example), which affects who controls pricing and carries inventory risk — so its approach to advertising isn't directly comparable to the other marketplace platforms. Even though we use the same word, "advertising," the billing mechanics differ by marketplace, and that's worth keeping in mind from the start.
"Selling well" and "ad spend that's working" are not the same thing
When revenue is growing on a given marketplace, you need to separate out whether that's the effect of ad spend or the result of other factors — seasonality, a promotion — unrelated to advertising. Adding more ad spend to a marketplace that was already selling well without ads can produce only a limited incremental gain. Conversely, on a marketplace where revenue clearly tracks ad spend, increasing the budget is more likely to be a sound decision. This distinction only becomes visible once you line up revenue, ad spend, and order volume across marketplaces.
You can't make allocation decisions without a cross-marketplace view
- Line up ad spend by marketplace against revenue and order volume for the same period, and check whether growth in ad spend correlates with growth in sales.
- Establish a baseline revenue level for periods without ad spend, and estimate how much of the increase is actually attributable to advertising.
- Assume from the outset that "highest revenue" and "best ROAS" aren't necessarily the same marketplace, and compare both side by side.
- Check whether ad spend is justified relative to real profit (after fees and return costs), not just revenue — judging by revenue-based ROAS alone tends to overvalue ad spend on marketplaces with high fees.
Manually reconciling ad reports and sales data every time, across marketplaces with different formats, is a heavy burden. Consolidating the data in one place and being able to continuously view ad spend, revenue, and real profit by marketplace is a realistic step toward more accurate allocation decisions.
Related reading
Why Comparing Revenue Alone Across Marketplaces Can Mislead You About Which One Is Actually Profitable
Ad-spend decisions only become meaningful once viewed alongside real profit (after fees and return costs), not revenue.
Suiliv Integrated Dashboard
See ad spend, revenue, and real profit across marketplaces in one place.
Frequently asked questions
Q. Should ad spend be concentrated on the marketplace with the highest revenue?
Deciding based on revenue size alone is premature. Increasing ad spend on a marketplace that already sells well without ads can produce only a limited net gain. It's worth checking how closely ad spend and revenue actually track each other before allocating budget.
Q. How should I compare ROAS across marketplaces?
Pull ad spend and results (clicks, orders, etc.) from each marketplace's ad dashboard and compare them against revenue for the same period. Since formats differ by marketplace, consolidating the data in one place before comparing makes this sustainable to run on an ongoing basis.
Q. Is revenue-based ROAS enough on its own to judge ad performance?
Revenue-based ROAS alone tends to overvalue ad spend on marketplaces with high fees. It's worth also checking whether ad spend is justified against real profit, after subtracting fees and return costs.
Facing this kind of challenge?
For sellers running two or more of Rakuten, ZOZOTOWN, and their own store (Shopify), we build a dashboard that consolidates data across marketplaces and deliver a weekly AI-annotated report focused on the metrics that matter for your industry. A free diagnostic is also available to check your current data-integration status.