Field Guide to a Product Mind: Social Proof

Jonathan Savage

Jonathan Savage

February 2, 2023

a webpage showing a group of people, with reactions like thumbs up, hearts, comments, likes, shares, and 4 stars

Before leaving the house, you grab an umbrella and coat after the woman on the morning news says to expect afternoon rain. 

You notice a long line of people waiting outside a new restaurant on your way home from work, and the next day call and make a reservation. 

Unsure of what to do on a Friday night, you decide to watch a movie or show, selecting from what’s “currently trending.”

What do the above have in common? They’re all examples of Social Proof and its influence.

What is social proof?

Popularized by Dr. Robert Cialdini in his seminal 1984 work Influence: Science and Practice, Social Proof is one of his aptly dubbed “weapons of influence,” or principles, along with Reciprocation, Commitment & Consistency, Liking, Authority, and Scarcity. 

In essence, the Social Proof principle suggests when a person finds themselves in an unfamiliar situation where they’re unsure of the correct course of action, they will often look to those around them for prompts and clues on how to behave properly. 

And although Cialdini brought the concept to the masses, this social and psychological principle has been influencing people for millions of years. Sometimes referred to as herd behaviour, social proof has been a successful survival strategy for humans. Just imagine it’s 100,000 years ago and you find yourself walking one way when you see all the members of your hunter-gatherer tribe running in the opposite direction, let’s say from a sabretooth tiger who’s just out of sight on the other side of the hill. 

What do you think happened next? Well, those who chose not to follow the example of their tribe exited the gene pool. Those who did are our direct descendants. And over time, their behaviour became so ingrained into who we are that it still influences us today, even without any real survival advantage. 

Accepting then that the Social Proof principle is indelible and inseparable from people, what are the mechanisms triggering it? 

What causes it

Much like strong winds and a clear sky make a model day for sailing, Social Proof too has ideal conditions in which the principle thrives. 

  1. Uncertainty: As I mentioned before, when people find themselves in a situation in which they do not know what they should do, inevitably, most will turn to the actions of others to guide their own. For example, if you’re hungry in a foreign country and don’t speak the language, just go to the busiest restaurant you can find and hope you have similar tastes to the locals. 
  1. Similarity:  Looking past proximity and people in the broad sense, the social proof principle is most powerful when the people whose behaviour is being observed are similar to us. A great example of this is teenagers – who are historically rebellious and go against the grain, that is, assuming it isn’t another group of teenagers we are talking about. In which case, personally, I have a hard time telling them apart. 

Social proof in action

Anytime a person uses a product – ANY product, there’s a presumed level of trust….

At the core of every product purchase, download, registration, or any other coveted conversion metric is trust. Because in a world where options abound and communication is broad and instantaneous, people need to believe the products they use will satisfy their end of the bargain. 


Customers - person holding up a purple shopping bag

When looking for social proof regarding a product, where better to turn to than the people who’ve used it – the customer. Social proof via a customer or user can take various forms, including user testimonials, case studies, social media shares, reviews, and ratings. For someone looking for honest answers, these can be of huge influence, especially if the potential user can relate not only their problem but themselves to the customer providing the proof. After all, there’s only so much convincing a product can do on its own. A great example of this is Amazon and Reddit reviews – although the former has come under scrutiny as many reviews are sponsored or paid, undermining trust both in Amazon and product reviews in general. Still, the fact there is a large organized enterprise based on aggregating paid reviews tells you how powerful social proof is as a behaviour.

Generally, customers are more apt to give a poor review or rating of a product than a good one, that is, unless you strategically present the opportunity to leave a review at the right time. The goal is to catch the user in a good flow state, and while this can be a very product-specific state to try and tap into, e-readers, fitness trackers, and their adjacent applications are notorious for this. Usually, the prompt will come after the application congratulates you for reading “X” number of pages or completing “Y” number of steps, with the goal of finding (and putting) the user in an elevated state of accomplishment and delight. This is also prevalent in mobile applications where rating requests pop up only during moments when the customer is invested in and had a positive experience around the value it delivers.

It should be noted that not all methods of customer social proof (or any social proof, for that matter) are created equal. Context and the product itself weigh heavily into which form would have the greatest impact. 


Experts - person in lab coat

Social proof via experts is, without question, the most difficult to manufacture but can also be the most powerful. Recommendations, testimonies, and industry expert endorsement; all heavily influence a user looking for a solution to a problem. But, as I mentioned, this is easier said than done. 

First, the product needs to be relevant to the expert’s particular field for an endorsement to hold any bearing. And if they are an expert and respected in their field, then they likely won’t put that in jeopardy by giving a testimony unless that product is, in fact, fantastic. 

While often the most credible authorities are experts with the accompanying education and credentials, sometimes those can be substituted by the relationship one has with the expert. How many of us turn to our mothers who didn’t go to culinary school for cooking advice, our best friends who’ve never produced a runway show for fashion guidance, or our coworkers who’ve visited exactly 0.05% of a country for travel recommendations?



Like it or not, and in many cases, whether they are users themselves or not, many celebrities and influencers have built up a near cult-like following, one that is heavily influenced by what they do, eat, wear, buy, go, and in some cases, just say. The power of this form of social proof is two-fold. First, and the most obvious, is the volume of exposure. Typically, these people have built up large, dedicated and engaged audiences, exposing a larger market to the product. And secondly, for these celebrities and influencers to build up such an audience, they need to have a positive relationship with that audience. Maybe they make music the audience likes, play for one of their favourite sports teams, or project an ideal or accomplishment that they themselves wish to achieve. Whatever it is, when it’s effective, social proof via celebrities and influencers becomes like a personal endorsement from a trusted friend. Remember that status is key here. Products engaged in building a brand identity will focus on how celebrity social proof can accelerate brand equity – which traditionally takes years to build.

Masses & Group Think

Masses/Group Think

While all forms of social proof are powerful, in some instances, its influence can be attributed to sheer volume. 

Imagine you are walking down a long street on a quiet day. As you make your way down, you notice somebody running in the opposite direction. You see an agitated look on their face, fearful almost, as they brush your shoulder, seemingly eager to get somewhere else. Shaking it off, you continue on your way when you notice another person running towards you in the distance. And then another. And another. Suddenly a swarm of frantic people is running towards you, leaving just enough time to saddle up against a storefront to get out of the way. 

What do you do then? 

I guess you would think twice about where you were going (or, more likely, wouldn’t think much at all) and instead rely on your herd instinct that’s kicked in, urging you to join the others. But join them in running from what? As yet, you don’t know if it’s a tidal wave, a 200-foot gorilla, or world war three that has compelled this group into a frenzy, and yet, you’re compelled to join them. This is the force that kept our ancient ancestors alive as they began to form and live in small groups, allowing their members to act quickly in the face of danger. It’s also the same force that drives the status-seeking lines outside of Apple stores and shoe stores ahead of a new release, which should have one asking if it’s the product or the proof that’s driving interest.

Another conventional example of this can be seen in digital products offering exclusive or limited features to a user base who act immediately on this scarcity simply out of FOMO (fear of missing out).



Not all social proof comes from people. As I mentioned earlier, there’s presumed trust when a person uses a product. After all, who would use a product that they believe won’t work? The answer is nobody. However, with the global marketplace ever expanding and knowing all products aren’t created equal, who are we to believe, and how do we know that their product will, in fact, do what they say it will? The answer is certifications.

Certifications are credentials given by an independent body that provides assurance that a product, service, system or company meets specific requirements. They also act as a proof point that substantiates the product’s claims, providing not only social proof but an assurance to would-be users of what they can expect. In other words, it helps take away some of the uncertainty around the product and the brand behind it. 

For example, I could go to the store and buy some steaks to cook for dinner. Or, I could go to a local butcher recommended by the Better Business Bureau and buy some  AAA-grade steaks to go along with my organic non-GMO corn, cooked using propane made from a certified B Company, served on a plate made of ethically sourced and fair trade materials, made by one of the countries best-managed companies who provide their workers with a living wage and delivered via a carbon neutral vehicle from a carbon neutral carrier, who also just so happens to plant ten trees for every delivery they make. 

While both scenarios above result in my family and I being fed, the difference is the second scenario takes away some of the ambiguity of exactly what I’m buying, how it is made, where it comes from and who is involved in the process. Often, we’ll see people look to these certifications to verify that a product or the company that makes it aligns with their values, such as fair trade certification, organic certification, and green certifications. “Stamps of approval” go a long way in dissolving uncertainty and distrust in a user or customer’s mind when deciding product fitness.

Final thoughts

Unless you wake up one morning suddenly knowing everything or completely alone on this planet, the power and influence of social proof will always exist. And while uses have gone beyond their evolutionary intent and are, in some cases, exploited by others, social proof remains a facet of our lives whether we like it or not. And it is the fact of this permanence, this constant and powerful influence it plays on us, that makes understanding it that much more important for product practitioners. 

Unfamiliarity and uncertainty are the biggest barriers to entry when launching a new product which is why product practitioners must be aware of these powerful means of overcoming them when building, testing, and validating new features. And that starts with product thinking and a product mind. 

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