Full Funnel Marketing in Cross-border EC: Investment Decision Based on ROAS and MER
As competition in cross-border EC market intensifies, limits are beginning to be seen in "point" measures by one-off ad operation. To realize sustainable growth in global market, perspective of full funnel marketing consistently capturing from awareness to purchase and fan creation is essential. In this article, we explain importance of strategic investment decision based on MER (Marketing Efficiency Ratio) showing overall investment efficiency, not sticking to short-term ROAS (Return On Ad Spend), from perspective of attribution analysis and incrementality.
Table of Contents (Click to Expand)
1. Necessity of Full Funnel Strategy in Cross-border EC
In overseas markets, if you lean too much toward last-click type "acquisition ads" with insufficient brand awareness, Customer Acquisition Cost (CPA) will inevitably soar. Especially in mature markets like North America and Southeast Asia, consumer customer journey is highly fragmented, and full funnel strategy based on MECE (Mutually Exclusive and Collectively Exhaustive) design of awareness formation in upper funnel, trust building in middle funnel, and conversion in lower funnel is key to maximizing mid-to-long-term LTV.
2. Limits of ROAS and Introduction of MER (Marketing Efficiency Ratio)
ROAS (Return On Ad Spend) for each ad platform tends to be overvalued in reaping measures such as retargeting. This is because it includes contact with users who were likely to purchase even without ads.
To measure true business growth, introduction of MER (Marketing Efficiency Ratio) is essential.
MER = Gross Revenue / Total Ad Spend
By grasping value of influencer marketing and pure ads, where attribution (contribution) is difficult to measure directly, correlatively as investment efficiency of entire business, bolder and more precise budget allocation becomes possible.
3. Social Commerce and Incremental Sales
In cross-border EC starting from TikTok or Instagram, even if ad contact does not lead to direct conversion, it creates "Incremental Sales" inducing search behavior and branded search. Evaluating these measures that would be cut off only by last click ROAS with Media Mix Modeling (MMM) thinking and increasing fluidity of entire funnel builds competitive advantage.
4. Framework of Investment Decision Based on Data
When making investment decisions on global scale, we recommend the following logical steps.
- Identification of Baseline: Calculate referral/organic sales (non-ad dependent sales) when ads are completely stopped.
- Incrementality Analysis: Confirm correlation between increase/decrease in ad investment and fluctuation index of total sales by multiple regression analysis etc.
- Setting MER Threshold: Calculate backward from marginal profit rate and set MER target as maximum investment line that does not damage business cash flow.
FAQ
- Q. What is the criterion for continuing ad investment even if ROAS drops?
- A. If MER of entire business maintains target value and Branded Search Volume is increasing, it is a signal that upper funnel investment is fostering future conversions. In this case, short-term ROAS decline should be accepted as investment phase.
- Q. Should criteria be changed for each country when introducing MER in cross-border EC?
- A. Yes. Since contribution margin differs depending on logistics cost, tariff, payment fee rate, and local competitive environment, setting MER threshold optimized for each country (region) is extremely important in global portfolio management.
Your Cross-border EC Business to Data Driven Growth
Experts support MER optimization and full funnel strategy planning in complicating global market.
Consult on Strategy for FreeSummary
Success of cross-border EC can no longer be achieved only by ROAS management of single platform. By building integrated full funnel marketing from awareness to purchase and setting MER (Marketing Efficiency Ratio) as North Star Metric, investment decision maximizing incremental sales growth becomes possible. Strategic approach based on data is the only solution in uncertain global market.
Published: 2026-1-15 / Author: Osamu Yasuda
References
- [1] Global E-commerce Strategic Investment Framework 2025
- [2] Marketing Efficiency Ratio: The New Standard for Digital Brands
- [3] Incremental Lift Analysis in Cross-Border Social Commerce

