From the notebook.

We tend to assume a simple rule in marketing: attractive people make ads more persuasive. So when we started studying how to promote crowdsourced products — those “designed by consumers” — we expected the same logic to apply. It didn’t.

Across five experiments, a consistent pattern emerged: attractive co-creators seem less authentic. People question whether they are real consumers or just models, and that skepticism reduces persuasion. They also feel less similar to the viewer, weakening the core benefit of crowdsourcing. In some cases, showing an attractive co-creator performed worse than showing no image at all.

What makes this especially interesting is that it is context-specific. The same attractive person works fine in a standard ad but backfires in a crowdsourced ad — because only there does attractiveness trigger doubts about authenticity.

Practical takeaways: don't assume attractiveness helps in crowdsourced campaigns; if the co-creator is highly attractive, consider not showing them, or style them to look more everyday; focus on authenticity and relatability, not polish. When the story is “designed by someone like you,” credibility beats beauty.

We spend a lot of time trying to make consumers smarter — teach them how ads deceive, train them to spot manipulation, help them avoid being misled. Sounds like an obvious win. But here's the twist: training consumers to detect one deceptive tactic can actually make them more vulnerable to others.

Across our studies, training people to detect fake experts helped them catch that tactic — but at the same time, they became worse at noticing other deception, like hidden qualifying fine print. It comes down to how attention and goals work: when you train someone to look for one thing, they focus on it, find it, mentally check the box, and stop searching. Psychologists call this goal shielding — one vigilance goal gets activated and competing detection goals get suppressed.

There's a way around this. Instead of training people on specific tricks, activate a broader mindset: general skepticism, critical thinking about ads, “look more carefully” rather than “look for X.” Detection of multiple deceptive tactics improves, with no negative spillover.

For marketers, regulators, and educators: don't over-rely on checklist-style warnings. Be careful with “watch out for this one trick” messaging. Prioritize general vigilance over tactic-specific training. You can win the battle and still lose the war.