Why Free Covid Tests Went Viral

This article is part of the On Tech newsletter. Here is a collection of past columns.

The hottest gossip this week was about swabs to shove up your nose.

When the U.S. government started a new website on Tuesday for people to order free at-home coronavirus tests, you might have heard about it from everyone. Moms texted their kids. Friends told one another in group chats, and then in different group chats. Perhaps your garden club told you.

There seemed to be a simple explanation as to why a government website received the attention that a new Beyoncé album might: We love free stuff, and many Americans have wanted home Covid tests but couldn’t easily find or afford them.

But people who study human behavior told me that there might be more to the story. The test kit website may have gone viral for some of the same reasons that a Black Friday sale can spread quickly: It makes us feel good to tell others something that may be helpful — especially if the information feels like secret knowledge — and we tend to trust people we know more than experts.

“We often see things that go viral and think it’s random luck or chance, but there are principles that make things more viral,” said Jonah Berger, a marketing professor at the Wharton School of the University of Pennsylvania and author of the book, “Contagious: Why Things Catch On.”

Dr. Berger said that when he saw people sharing information about the test kits, he recognized many of the same human tendencies that businesses harness to spread the word about a new product.

The “secret” menu at the fast food chain In-N-Out Burger is not a secret. Instead, Dr. Berger said, it’s clever marketing that capitalizes on the zings of pleasure that we get — whether we’re aware of the strategy or not — from passing on what seems like hidden information.

That’s also how gossip spreads, and why we were inclined to tell friends where we bought toilet paper when it was hard to find.

We’re also more likely to share information about a topic that arouses fear or other strong emotions. And of course, when products are exclusive or we believe that they’re scarce, it makes us more eager to get in on the action. The coronavirus test kits check all those boxes.

Jessica Calarco, a sociology professor at Indiana University, also told me that people are inclined to base their health decisions on the actions of people they know, or people they believe are like them. Social pressure — like hearing about the coronavirus test website repeatedly from friends and family — can be more influential than official health recommendations or advice from doctors.

News about the coronavirus test website “was primarily spread person-to-person in a more informal way, creating social pressure to participate and inspiring trust in the system as a whole,” Dr. Calarco told me.

Harmful rumors and conspiracy theories can spread for similar reasons. We’re more inclined to pass on news that scares us, and we like to feel in the know and as though we’re helping. Misinformation researchers warn about rumors that seem to come from “a friend of a friend,” because we’re more likely to trust a claim that appears to come from our social connections.

This week, though, was another example of the way in which the same behaviors and tendencies that help sell hamburgers and spread gossip can also persuade many millions of Americans to contribute to the public good.

If you don’t already get this newsletter in your inbox, please sign up here.

Tip of the Week

Speaking of stirring strong emotions, Brian X. Chen, the consumer technology columnist for The New York Times, is here with advice on stepping up your digital security.

This week President Biden shared his prediction that Russia would soon invade Ukraine, whose computer networks have recently been the target of a far-reaching cyberattack. It’s unclear what this all means for the United States, but security experts have warned that Ukraine had been a testing ground for Russia’s cyberattacks, meaning the same attacks could eventually reach Americans.

That’s all hypothetical right now, but it’s another good reminder to beef up the protection of your online accounts. The best thing you can do to protect yourself is to make sure your online accounts are signed up for two-factor authentication; this adds a step to verify that you are who you say you are. Even if a password falls into the hands of the wrong people, they cannot pretend to be you.

In a past column, I covered various methods for setting up two-factor authentication. One of the strongest setups involves using an authenticator app.

Here’s an example of how to set up an authenticator app with Facebook:

  • On your phone, go to your app store and download a free authenticator app, like Google Authenticator or Authy.

  • Then, on Facebook’s website, go to your security and login settings. Click “use two-factor authentication,” and then click “edit.” Choose the option for an authentication app as your security method. From here, follow the onscreen instructions.

  • From now on, whenever you log in to Facebook, you can open the authenticator app and look at the temporary six-digit code generated for your Facebook account. You must enter this code in order to log in.

Setting up two-factor authentication on all your online accounts is a hassle. But after you set it up the first time, it’s a breeze. Prioritize your most sensitive information, like your online banking accounts.

  • The clock is ticking on Congress: Time is running out for legislators to pass bills to put guardrails on America’s technology giants, my colleagues Cecilia Kang and David McCabe report. Democrats support legislation targeting the tech industry in far greater numbers than Republicans, and they could lose control of Congress this fall.

  • What happened to the Instant Pot that you returned?: NPR’s Planet Money podcast followed two nursing school students who line up each week at a discount store to buy and then resell merchandise that people bought online and returned. Be prepared for the sounds of competitive shopping, and a lesson in the complexity and costs of the stuff that we regret buying.

  • The people who buy nothing and want to break their dependence on Facebook: “Buy Nothing” groups that offer free bowling balls or leftover pickle juice to their neighbors are among Facebook’s most avid communities. The Verge reports on efforts by some of the groups to form their own online spaces separate from Facebook.

A woman in Canada was reunited with her cat 12 years after it disappeared. Twelve years!

We want to hear from you. Tell us what you think of this newsletter and what else you’d like us to explore. You can reach us at ontech@nytimes.com.

If you don’t already get this newsletter in your inbox, please sign up here. You can also read past On Tech columns.