DeNA's WELQ ran medical misinformation as SEO bait — 9 sites closed, ¥3.9B write-off

In late November 2016, doctors and readers began pointing out that WELQ — DeNA's medical and health information site, part of its curation-media push — was publishing articles with no medical basis, some of them presented as doctor-supervised without any real supervision. What was meant to be dependable health advice was, in effect, content-farm traffic bait.

The response escalated within days: on 29 November DeNA suspended all WELQ articles and apologized; on 1 December it closed WELQ and eight other curation sites at once, with president Isao Moriyasu apologizing and promising nothing would resume without proper medical review. The scandal became one of Japan's defining content-marketing failures — a reminder that SEO-driven publishing cannot be trusted with people's health.

The bill arrived in February 2017: DeNA booked a 3.859 billion yen impairment loss on the suspended curation business, after an operating loss of about 1.69 billion yen in the segment through December 2016. Its full-year operating profit forecast was cut from 22.3 billion yen to 18.6 billion yen.

Shut all nine curation sites at once and booked a ¥3.86B impairment, betting that killing the whole network would restore trust faster than fixing one site.

WELQ chased page views: articles were produced fast for SEO, and medical claims were published before any expert review existed.

The site looked trustworthy — presented as doctor-supervised — so readers treated search results as medical advice.

DeNA's curation model scaled across nine sites at once, so one exposed site took the whole network down with it.

Page views are not permission to publish. When the content is health advice, SEO optimization without medical review turns a traffic bet into a trust collapse — and a ¥3.9 billion write-off.

DeNA suspended all curation media indefinitely, later sold the remnants of the business, and set up a medical-review structure before any health content could resume. The episode pushed the Japanese government to tighten rules on doctor-supervised medical information online.