Ah, here it is. They scan people's emails/inboxes. > Slice Intelligence data comes from several sources, including the receipts in the e-mail inboxes of consum

Ah, here it is. They scan people's emails/inboxes. > Slice Intelligence data comes from several sources, including the receipts in the e-mail inboxes of consumers who use the popular Slice online shopping service, Slice, and through strategic partners, including users of Slice’s API platform. Each e-mailed receipt contains a treasure trove of data. Yeah no doubt reading people's emails is a treasure trove of data.