Two words, "lookalike modelling", or as FB calls it Lookalike Audiences: https://www.facebook.com/business/help/164749007013531 https://www.facebook.com/busine

Two words, "lookalike modelling", or as FB calls it Lookalike Audiences: https://www.facebook.com/business/help/164749007013531 https://www.facebook.com/business/help/164749007013531 Arcade Foobar want to draw in new customers, and so generate a lookalike audience based on data they have from existing customers. The modelling algo then compares data points for people who 'look like' their customers, and those people can then be targeted with a high probability that they will also be interested in the same thing. This is a perfectly plausible explanation that doesn't require FB to be listening to you through your phone mic.