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You are prohibited from creating ad content which implies knowledge of personally identifiable information or sensitive information about your customers ... Sensitive information about your customers can’t be used in Customer Match campaigns or ads. Additionally, you can't use data from your Customer Match campaigns to identify sensitive information about your customers. Sensitive information includes: Interest or pa…
There is actually a creep-out effect with taking this too far I think that drives people away from ads that are too stalkery. Consider the case of target who toned down the exactness of some of their targeted mailer ads to women likely to be pregnant after accidentilly kicking off the outing of a pregnant teen to her family. Perhaps we should be more creeped out by the more subtle personalized ads than the clumsy att…
As for the more subtle way of using this personalization will be to stick more ads in the faces of people that once signed up for a service but don't use it as much these days and don't open the reminder/newsletter emails that end up in their "social" or "promotions" tabs. I found this sort of badgering with traditional ad retargeting creepy enough to drive me to install an ad-blocker, but it undeniably works and is heavily used by companies that care about their reputation.