Sources: Yahoo's Oath has been pitching advertisers on a service that analyzes its 200M+ Yahoo Mail, AOL Mail inboxes; source says practice began 10+ years ago
Web giant analyzes more than 200 million inboxes for clues about what products people might buy—a practice much of Silicon Valley has declared off-limits Tweets: @wsj , @djtgallagher , and @reaganbrad Tweets: The Wall Street / @wsj : Google stopped. Microsoft says it never did it. Only Yahoo still scans emails, a practice it has expanded over the years. http://www.wsj.com/... Dan Gallagher / @djtgallagher : Wonder how much Verizon's purchase of Yahoo and AOL was premised on the idea that people never kill old email addresses. https://www.wsj.com/... Brad Reagan / @reaganbrad : Tasty nugget here: Amazon stopped sending customers itemized receipts because it didn't want Yahoo finding out what people were buying by sorting through their email. Good work from @dmac1 @bysarahkrouse and @keachhagey https://www.wsj.com/...
Context & Ripple Effects
The pitch lands at the center of why Verizon bought Yahoo and AOL in the first place: its stated goal was to compete with Google and Facebook in digital advertising by sharing customer data with advertisers (Verizon's stated aim of competing with Google and Facebook through shared data). Inbox scanning is the asset that makes that ambition concrete — 200M+ Yahoo Mail and AOL Mail inboxes read for purchase intent.
The report also fits Yahoo's pattern with email data. Two years earlier, sources described a system built in 2015 to scan users' emails for a specific string for US intelligence, which triggered Alex Stamos's resignation — evidence that inbox-level scanning was already institutionalized inside the company before Oath commercialized it.
First-order effects
- Oath can offer advertisers purchase-intent targeting drawn from more than 200 million inboxes — a dataset Google has walked away from and Microsoft says it never touched, making Oath the last major seller of scanned-email ad data.
Second-order effects
- Counterparties are already defending themselves: Amazon reportedly stopped sending itemized receipts specifically so Yahoo could not infer purchases from them, showing how the practice distorts behavior across adjacent companies.
- Google and Microsoft's public disavowals turn Oath's differentiator into a reputational liability, pressuring advertisers to weigh cheap inbox-derived intent against brand-safety exposure.
Third-order effects
- If the pattern holds, email scanning splits the ad market into platforms that voluntarily forgo inbox data and laggards that monetize it — inviting regulators and privacy norms to treat inbox contents as the next contested targeting surface, much as the earlier intelligence-scanning episode previewed government interest in the same pipe.
The trend: Consumer inboxes are becoming a contested ad-targeting asset: the biggest platforms are unilaterally withdrawing from email scanning while consolidators like Verizon's Oath double down on it.