Thread by @dmac1

We wrote about Yahoo scanning emails for ad targeting:
wsj.com/articles/yahoo…

Here’s how it works…
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Billions of messages arrive in Yahoo Mail and AOL Mail every day. Yahoo’s parent company Oath scans them all, ignoring personal messages and looking for commercial templates it recognizes

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Anyone who receives a receipt from Macys.com may get a cookie placed on their computer identifying them as a department store shopper. Anyone getting a trade confirmation from ETrade.com may get an “investor” cookie.

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Oath sells marketers on the ability to show ads to these users across the web — not just inside email. Advertisers can only reach users based on cookies, not user names or personal information

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The system is not foolproof. At one point, Yahoo mislabeled Indian wedding invitations as commercial mail, because they are often form emails sent to many people.

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The practice is controversial. Google used to scan emails for ads it showed inside Gmail, but stopped a year ago. Microsoft never scanned emails for ads. Amazon didn’t want Yahoo to scrape purchase data in its customer emails, so its stopped sending itemized receipts in 2015

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Yahoo charges $3.49 a month for Yahoo Mail Pro, an "ad-free" version of its email service. But Oath says those users also have their emails scanned by default.

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If you're a Yahoo Mail user, you can opt out of all email scanning by clicking a button on this page:
aim.yahoo.com/aim/us/en/opto…

/The end