I have no idea. Doesn't seem implausible to me. Apparently, ≈75% of the world population has internet access now. And if a person has internet access, is it that unlikely that he was successfully targeted by at least one of these idiotic marketing campaigns (turn your photo into a barbie doll or whatever)? 10% sounds plausible to me, more or less. So maybe not really literally a 1B, but doesn't need to be very far from the real numbers, IMO.