The drive to get the country vaccinated against COVID-19 has provided a fascinating insight into what motivates people. Different states have tried lotteries, giveaways (cash, trips, fast food, beer, donuts, even marijuana joints), college scholarships, and endorsements of football coaches. Interestingly, a Wharton study found the specific text used in a message had an oversized impact in prodding people to come in for a jab: By a wide margin, the top-performing message conveyed that a vaccine was “reserved for you.” It’s a message jewelers can tweak and use themselves. “Your jeweler is back from the world’s largest jewelry show. The latest designs, selected with you mind, are waiting for you.” Or if that doesn’t work, perhaps try that free joint.