When considering the factors that are required (or at least helpful) for a lie to succeed, I constantly look to the audience. I constantly try to take inventory of the nature of its members. It's easy to generalize the gullible as willfully ignorant, as unwilling to see things as they are. And there's probably truth in that.
But generalizing like that prevents us from asking about the circumstances that led to their willingness to be ignorant. How do you encourage someone to forego their curiosity in order to simply consume whatever's said to them? For me, curiosity seems to be the enemy of the lie. Curiosity is the antidote.