> We will require a crowd of 50 users per creative within the past 7 days before the ad can be rendered. Am I missing something? 50 is not a big number. And 5

> We will require a crowd of 50 users per creative within the past 7 days before the ad can be rendered. Am I missing something? 50 is not a big number. And 50 over 7 days is less than one per three hours, which suggests that coarse-grained time-based attacks or simply changing the targeting every few hours could end up effectively targeting a single user. Or just asking for the ad 49 times before unleashing it?