Seller's Concern

COSRX is a K-beauty brand with a powerful fanbase in the Japanese Amazon skincare market. Known for leading with low-irritant, high-efficacy ingredients, the brand holds a strong competitive position — with its flagship product, Advanced The Vitamin C23 Serum, maintaining a top-ranking position in its category and earning high trust among local consumers.

Managing a wide product portfolio, COSRX had been running campaigns with fragmented budget allocations and updating keyword lists manually on a weekly or monthly basis. As the number of products grew, so did the operational burden — making precise efficiency management increasingly difficult.

LG Optapex Solution

Optapex started by restructuring COSRX's complex product and promotion-level campaign architecture.

① 16 products, one system — managed together

All Opt. sets were unified under a single optimization goal: Maximize Ad Sales. With the Boost Impression option activated, the focus was on aggressive impression growth.

By building individual Opt. sets for each of the 16 products, the system adapted to brand-level conditions through continuous learning — enabling independent performance tracking per product while keeping all operations aligned under a single goal and framework.

② Performance maximization through promotion-aligned ad management

Each Opt. set was configured with one ASIN, with separate budget schedules set according to each product's promotion calendar.

Even with frequent budget changes throughout promotional periods, campaigns were executed and paced without issue. As budgets concentrated during high-conversion promotional windows, ad sales growth and efficiency improvement were achieved simultaneously.

③ Fast stabilization from day 1 — by connecting existing keywords

Proven keywords from existing campaigns were immediately imported into Optapex via the Keyword Integrate feature.

This significantly shortened the initial keyword harvesting phase. By maintaining a manual campaign share of 70% or more even during the learning period, optimization stabilized in a short period of time.

Results

As a result, total sales grew by 179% and ad sales by 71% — while maintaining ad spend at existing levels. ROAS improved by 212 percentage points, and both CPC and TACoS saw meaningful gains, delivering efficiency and growth at the same time. (January-March 2026)

This was achieved while simultaneously overcoming the limitations of manual operations — realizing product-level optimization and full account efficiency management in parallel.

“We saw results that exceeded our expectations. We started with our key products, expanded the lineup after confirming performance, and are now planning to migrate our entire campaign operation to Optapex.” — COSRX Brand Manager

Conclusion

The ability to complete optimization in a short time — across a diverse product lineup and tight promotional schedules — was made possible by restructuring operations at the product and promotion level, and by connecting keywords that had already been validated.

Even if it's your first time adopting a solution, with Optapex, you can get up to speed quickly.