Why Do I Want to Buy Everything That Goes Viral? Social Proof and FOMO, Explained

Picture this. You're scrolling TikTok in bed and land on a post that says "if you didn't grab this during the Sephora sale, what are you doing?" There are over 200 comments, all some version of "same, got it" or "it was sold out so I hit three stores." Your old lip balm is sitting in your drawer, perfectly fine, but your thumb is already opening the app. It's only when the order confirmation pops up that you think, "wait, why did I buy this?"

With sales and pop-up shop openings stacking up several times a month, nights like this happen a lot. It's worth asking whether that's a willpower problem or just how human brains work. Social cues can influence everyday choices, but they do not explain every purchase or prove that people are wired to buy whatever trends. It helps to ask whether the item meets a need of yours, beyond the popularity around it.

Why "everyone bought it" sounds like information (social proof)

Robert Cialdini, the persuasion researcher best known for Influence, explained that when we're not sure what to do, we look at what other people are doing and guess the right answer from that. That's social proof. It's the same call you make when you walk into the restaurant with the long line in a neighborhood you don't know. Most of the time it's a pretty useful shortcut.

An old experiment shows it well. Milgram, Bickman, and Berkowitz (1969) had confederates stand on a busy New York street and stare up at a sixth-floor window across the way for 60 seconds. When one person was looking up, only 4% of passersby stopped. When 15 people were looking up, 40% stopped. And the share who at least glanced up, even without stopping, went from 42% to 86%. There was nothing in the window.

That was a 1960s street experiment, so you can't map it straight onto online shopping today. The direction is clear, though. The more people are staring at something, the more people decide "there must be something there." Those 200 comments under a viral post are doing the job of the 15 people on the sidewalk.

And sometimes this shortcut works fine. If you're buying sunscreen for the first time and the ingredient list means nothing to you, starting with something that has lots of consistently good reviews is a pretty reasonable move. When you don't have information, other people's choices are a decent starting point. Beauty and merch, where new products drop constantly, are markets where information is thin to begin with, so that's even more true there.

The problem is that this shortcut lets you skip the question "do I actually need this?" What other people liked might tell you something about quality. It tells you nothing about what's already in your drawer.

Popularity has more luck in it than you'd think (the MusicLab experiment)

So can we at least assume that things that sell a lot are good? The Salganik, Dodds, and Watts (2006) experiment speaks to exactly that. The researchers built a website with 48 songs by unknown bands and let more than 14,000 people listen and download. Some participants picked songs without seeing any download counts. The rest were sorted into one of eight independent "worlds" where download counts were visible.

Two things happened. First, in the worlds with visible counts, the gap between hits and flops got much wider. Second, the same song could rank very differently from world to world. Depending on who happened to download it early, a song might be number one in one world and middle-of-the-pack or lower in another. The very best songs rarely sank to the bottom and the very worst rarely hit the top, but anything in between could happen.

There are limits. Participants were online users getting songs for free, which isn't the same as spending money. Still, it fits viral posts pretty well. That "sold out everywhere" item might have blown up because it's great, or because a few early reviews happened to get a lot of likes and it snowballed from there. Add a recommendation algorithm that shows popular things to even more people, and the pile-on gets bigger. Our post on

It hits harder when the buyer seems like you

Why do community reviews feel more trustworthy than a polished ad? Because the person writing them looks like "someone like me." When someone in the same fandom, around your age, with the same skin issues says "this is actually good," it lands a lot closer than any ad copy.

Goldstein, Cialdini, and Griskevicius (2008) hung different versions of a towel-reuse card in hotel bathrooms. A message saying most guests reused their towels worked better than a general appeal to protect the environment, and narrowing it to "most guests who stayed in this room" pushed reuse up further. The takeaway was that we're more likely to follow the behavior of people whose situation is close to ours.

Don't lean on that result too hard, though. When Bohner and Schlüter (2014) ran the same experiment in two German hotels, the "most guests reused" message wasn't clearly more effective than the standard environmental message, and the "this room" effect has been inconsistent across studies. The direction makes sense, but the size isn't something to count on.

Community reviews have one more trap. The review that sounds just like you might be sponsored, or the person's skin type and use case might be completely different from yours. That "they're like me" feeling can come from nothing more than a username and a tone of voice.

So when you read reviews, check the context before the stars. A review that says something like "oily skin, used it in summer, three weeks in" is worth more than ten "holy grail!!" posts. If reviews with that kind of detail are hard to find, the hype is still mostly vibes.

Where the fear of missing out comes from (FOMO)

Tack on "limited stock," "today only," or "1,000 people already bought this," and your decision speeds up even more. The name for that feeling is FOMO, the fear of missing out. It's the anxiety that other people are having good experiences and you're the one left out.

Przybylski, Murayama, DeHaan, and Gladwell (2013) built a scale to measure it and surveyed people across a range of ages. People who said their basic needs for competence, autonomy, and connection were less satisfied tended to score higher on FOMO. And higher FOMO went along with checking social media more often and reporting lower mood and life satisfaction. It was a one-time survey showing correlations, so we can't tell which came first.

Still, one thing's worth thinking about. When your friends keep posting the same pouch in the group chat and you're the only one without it, is it really the pouch you want, or the feeling of being part of it? It's the same thing when a pop-up opens and your feed fills up with "we're #300-something in line" posts. You feel like you missed something by not going, even though you can't quite remember what you wanted to buy there.

What to try before you hit "buy" (the 24-hour cart rule)

These aren't research-tested prescriptions. They're everyday tricks that turn the ideas above around and use them in your favor. If viral posts rush your decision, the fix is to add time to it.

1. Put it in your cart and wait 24 hours

Don't delete it. Just leave it there. "I'll buy it tomorrow" is a lot easier to stick to than "I'm not buying it." The most common pushback is "what if it sells out?" If the urge fades in a day, you won't miss it much if it does. On the flip side, things you've already thought hard about, like an album or concert merch you've been waiting on for months, can skip this rule.

2. Run through five quick checks

• Did I think I needed this before I saw the post?
• Do I already own something similar?
• Are the reviewer's circumstances (skin type, where they use it, budget) actually close to mine?
• Is there a sponsorship tag, or the exact same phrasing showing up over and over?
• Would I buy this even if nobody else had?

If you hesitate on the last one, chances are it was "everyone" pulling you in, not the product.

3. Have one sentence ready for yourself

"I'll use this when I ___, and it'll replace the ___ I already have." If you can't fill in the blanks, it stays in the cart another day.

4. Change what you ask the group chat

Ask "should I get this too?" and you'll mostly hear "yes!!" Instead, try "if you've used it, tell me one downside." Once you start collecting complaints instead of praise, the decision gets a lot calmer.

5. Set one monthly budget for trendy stuff

Pick whatever amount fits your situation. The point is agreeing with yourself that anything within that limit is guilt-free. More rules are harder to keep, so make this the only one.

Sometimes these tricks won't be enough. None of this is a diagnosis, but if you keep buying things and regretting it, if card bills are shaking up your day-to-day life, or if you're juggling debt to pay off other debt, it's better to get help than to grit your teeth through it alone. A nonprofit credit counselor (for example, one affiliated with the NFCC in the US) can walk you through your options. If money stress is wearing you down emotionally too, you can call or text 988 (the Suicide & Crisis Lifeline in the US) any time, day or night. Outside the US, contact your local emergency number or find a line at findahelpline.com.

Wondering whether you're drawn to the thing or the connection?

If there are stretches when you're especially weak to whatever's trending, it might be worth looking at what feels missing in your relationships lately. The Emotional Needs Test shows how the signals that make you feel loved, safe, and understood differ from person to person. The result isn't a diagnosis that defines you. It's enough to use it as a hint about what you've been thirsty for lately.

There'll be another viral post tomorrow

Getting swayed by "everyone bought it" isn't weird. Looking at others when you're unsure is something people have done forever, and most of the time it helps. It's just that popularity has more luck in it than you'd think, and the reviewer who seems like you might actually be in a pretty different spot.

So the next time a viral post catches you late at night, put the thing in your cart and flip your phone face down. If you're still thinking about that lip balm tomorrow morning, go ahead and buy it.

Sources

• Milgram, S., Bickman, L., & Berkowitz, L. (1969). Note on the drawing power of crowds of different size. Journal of Personality and Social Psychology, 13(2), 79–82. https://doi.org/10.1037/h0028070
• Salganik, M. J., Dodds, P. S., & Watts, D. J. (2006). Experimental study of inequality and unpredictability in an artificial cultural market. Science, 311(5762), 854–856. https://doi.org/10.1126/science.1121066