m19 Japan: +569% sales for Aster One with automated bid management

When Aster One prepared to launch an upgraded version of its flagship products, the Japanese brand — best known for its innovative Kamika cream shampoo — faced a key challenge: encouraging loyal customers to adopt the new formula while still supporting sales of the existing lineup.

Before this new release, Aster One managed its advertising campaigns on Amazon manually. But to successfully handle a product transition at the ASIN level, manual adjustments quickly became too time-consuming and prone to error. To gain more precision and scale, the brand turned to m19, the AI-powered ad automation platform operated by m19 Japan.

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Our approach

• We first broadened the range of keywords used in Aster One’s campaigns. Previously, the brand focused mostly on branded keywords. With m19, hundreds of new non-brand keyword combinations were automatically created and linked to individual ASINs. Thanks to conversion predictions and daily bid adjustments, m19 expanded targeting opportunities — driving uplifts in both sales and ROAS.
• In parallel, we activated Sponsored Display remarketing: shoppers who had viewed the previous product version were retargeted with ads showcasing the upgraded one. This created a smooth transition path toward the new product while maintaining visibility for the older SKUs.

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Key results (4-month period)

• +569% ad-attributed sales for the upgraded products.
• Non-brand keyword conversions increased from 9 to 533.
• Branded keyword variations expanded from 114 to 680.
• Even with reduced investment on legacy products, their sales still grew by +102%.
• Active branded keywords increased from 9 to 80.
• ACOS dropped from 67% to 20%.

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By relying on m19, Aster One successfully transitioned customers to its new product range without cannibalizing existing sales — while significantly improving overall advertising performance.

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👉 Read the full business case on Amazon's website here

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m19 Japan

This success story was carried out by m19 Japan, our local branch launched in 2023 and led by Masaki Iino and Kaori Iino. With our on‑the‑ground presence and deep expertise in the Japanese e‑commerce market, we were able to support Aster One in carrying out a smooth ASIN-level relaunch on Amazon Japan — leveraging automated bid management, smart keyword expansion and remarketing strategies to maximize impact.

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Amazon performance in the Japanese market

In Japan today, e‑commerce continues to grow at a fast pace. The country’s B2C online retail market reached roughly ¥ 27.4 trillion (≈ US$ 245 billion) in 2024. ULPA+1
Amazon Japan remains the undisputed leader among online marketplaces: with around 602 million visits per month (2025 data), it claims a significant share of the online shopping traffic. ULPA+1
Additionally, Amazon Japan is estimated to hold roughly 25% of the total Japanese e‑commerce market — thanks to its vast product selection (hundreds of millions of SKUs), reliable logistics network, and a high level of consumer trust and convenience. ULPA+1

Given this scale and influence, Amazon Japan represents a critical growth channel for any brand targeting Japan. Having a dedicated local partner like m19 Japan — with local knowledge, cultural insights and operational execution capabilities — therefore makes a real difference when launching or relaunching products on the Japanese market.

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