Mercari Ads: A New Player in Japan’s Online Retail Media Market

Merucari

On February 6, 2025, Mercari officially launched Mercari Ads, marking its entry into Japan’s rapidly growing online retail media market, which is projected to exceed ¥1 trillion by 2028. With 23 million monthly users, Mercari now offers a click-based advertising platform designed to help brands connect with engaged shoppers.

Mercari Ads: A New Way to Reach Engaged Shoppers

  • Product Ads – Shown within search results and product listings, targeting high-intent shoppers.

  • Infeed Ads – Customizable image and text ads displayed in users’ browsing feeds.
  • On-Site Ads – Boosts visibility for Mercari Shops listings within search results.

The Rise of Online Retail Media in Japan

Online retail media—ads placed directly within e-commerce platforms—is one of the fastest-growing segments in Japan’s digital ad market. While Amazon, Rakuten, and Yahoo! Shopping have long dominated, Mercari’s entry expands opportunities for brands, particularly those targeting deal-seeking and price-conscious shoppers.

What This Means for Marketers

✔ High Purchase Intent – Ads reach consumers actively searching for products, leading to higher engagement and conversion rates than traditional display ads.

✔ First-Party Data Advantage – Unlike social media ads that rely on third-party tracking, retail media leverages direct consumer shopping behavior, allowing for more precise targeting.

However, while Mercari is widely recognized for secondhand and discount goods, premium brands may need to assess whether the platform aligns with their positioning. For brands focused on affordability, promotions, or outlet sales, Mercari Ads presents a high-potential opportunity in Japan’s evolving online retail media landscape.

Other News

Yahoo! Shopping products can now be tagged in YouTube videos
LINE Yahoo announced on September 25 that Yahoo! Shopping has joined the YouTube Shopping affiliate program (MarkeZine, September 25). Eligible YouTube creators can tag Yahoo! Shopping products in videos and Shorts. Viewers tap the tag and land on the product page. Stores pay a base rate of 2–4% by category and can add a special rate of their own. YouTube says shopping-video watch time in Japan grew more than 50% year on year (internal data, April 2026).

For foreign brands in Japan, this puts Yahoo! Shopping on the same creator shelf as Amazon and Rakuten. Creators choose the store with the higher rate. Set a special rate on your hero SKUs before Q4.

▶ MarkeZine (September 25)

Yahoo_Shopping_Products_tagged_in_YouTube_video

Survey: 52.3% of Japanese respondents search with generative AI
52.3% of 9,278 respondents aged 15–69 use generative AI, including Google AI Mode, for search (AdverTimes, September 9; fielded August 7–10). The figure was 21.3% in May 2025. 58.7% say an AI recommendation led to a purchase. One survey, one vendor, but the direction is consistent with earlier waves.

For foreign brands in Japan, the AI answer is becoming a purchase touchpoint. Check how ChatGPT, Gemini, and AI Mode describe your products in Japanese before Q4.

▶ AdverTimes (September 9, 2026)

Japanese Consumers Search on Generative Engines

OpenAI added product carousels to ChatGPT ads, showing several items in a single ad slot.
The format arrived three months after OpenAI let retailers bulk-create product-feed campaigns.

OpenAI’s system decides whether a query returns a single-product ad or a carousel — the advertiser does not choose. For brands in Japan, that moves the work upstream to the product feed. Japanese product names, prices, and stock status decide what appears. Audit the feed before year-end trading.

▶ DIGIDAY Japan, August 17, 2026.

ChatGPT Carousel mock-up