Social Proof Marketing: The Dos and Don'ts

Everybody knows what social proof is, but not everyone knows what not to do. Until now.

Patrick Oberstadt | Oct 10, 2018

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Marketers love the idea of social proof, the magical tactic that makes your customers more likely to click or, hopefully, convert. Seems like an easy fix when it comes to implementation, and sometimes it is, but not always.

Countless marketers rave about the success stories of social proof. However, most of these articles just scratch the surface of what is actually at play when social proof is used in the process of psychological marketing.

How many of these go into depth about why this mechanism actually works? What are the reasons for its effect? If it doesn’t always work, what causes this?

Let’s shed some light on this subject to go deeper than the usual tip of the iceberg.

Why does social proof work?

Alright, for those that need a reminder:


Social proof is a psychological and social phenomenon where people assume the actions of others in an attempt to reflect correct behavior in a given situation.


In short, people look at others to decide what to do. It is found to be very effective for marketing and eCommerce efforts, therefore, it is praised and written about by virtually the entire marketing community.

It was originally popularized by Robert Cialdini. But eventually, it spread around the world as it was implemented in countless stores, webshops, and other organizations seeking to persuade their audience.

Some use the tactic by showing the number of product likes, reviews, or endorsements from other people. Others use social proof by just using words like “bestseller,” “most viewed,” or “hot right now.” These words implicitly say it’s a popular choice and thus a good place to start a product search.

Social proof is a well-known persuasion technique, but not all of its sides have been made public. This makes it all the more interesting to dive into the mechanics that make this technique so effective and discuss the situations that it simply doesn't work.


When social proof is most effective

When buying items online, there are different types of shoppers and products. Not everyone needs social proof to help them guide their decisions. But a lot of people like this as a cue to aid them when a choice is presented.

Social proof can be especially effective in the following situations:

  • In unfamiliar territory as quality assurance
  • As a form of social validation
  • When used for functional, non-expressive products
  • For gift shoppers

Naturally, there are many other situations that social proof can be a winning persuasion technique. But as these are already very well documented, let’s focus our attention to these areas.


1. Social proof works in unfamiliar territory as quality assurance

quality assurance social proof

Let’s say someone goes on a holiday to Barcelona for the first time but doesn’t know which hotel to book. Having an (honest) message saying that an option is popular or a bestseller will probably prompt them to investigate the hotel.

Why does this work?

When shopping online, individuals can’t evaluate the product directly. So if someone is unfamiliar with a specific product, they tend to rely on external cues and follow the buying behavior of other consumers.

Popularity cues, therefore, provide reassurance of the quality of the product and can enhance a person’s purchase intentions. Plus, consumers are likely to think that the more popular alternatives are of superior quality because the link between popularity and quality is so intuitive that this association is automatic.

This is not only the case when looking for a travel-related product. Social proof can work just as well for individuals who want to buy a fashion item. Similar to word-of-mouth, when someone buys fashion products online, popularity cues can be used as a strategy to reduce risk and eliminate uncertainty about the quality of the brand’s clothes.

2. Social proof is a form of social validation

social validation social proof

Consider the Mean Girls scenario. You arrive at a new school, in a new country and culture, and are searching for a path to social approval. Naturally, the easiest way to the teenage heart is to conform to their style.

So, when you hear, “On Wednesdays we wear pink,” you’re going to find a way to make that a reality. Because, obviously, this is the most fetch (“Gretchen, stop trying to make fetch happen! It's not going to happen!”) thing you could do.

Mean Girls references aside, the same goes for eCommerce. Popularity cues signal to potential buyers that many people have bought the product and provides social validation for the product that is labeled with a social proof message. This means that by buying a socially “approved” product, you are likely to be accepted by doing so, reducing the chance that you are negatively judged.

This social validation is appreciated more by people who score high on the trait of self-monitoring. High self-monitors are concerned with how well products present their identity and what the perceived image is of others when they own said product.

Knowing you have a self-conscious audience that cares about what other people think when they use your products is important. Maybe a hard statistic to come by, but very insightful nonetheless.

3. Social proof works well for functional products

social proof functional

So what about product categories besides those found in fashion and travel? Are those looking for functional products like vacuums or laundry detergent also susceptible to social proof?

A million times, yes.

When buying these non-conspicuous products (products that one doesn’t attach their social image to or identifies to), popularity cues can actually enhance the perceived quality and thereby improve the attitude towards the brand and product.

The same rules apply as with the previous industries: Under conditions of uncertainty, we often rely on others for information about whether we’ll like something. This might lead people to align with the majority in functional, non-identity product categories (like drills, vacuum cleaners, or laundry detergents).

Someone buying a drill for the first time? You can bet they know very little about drills and need help from others to make the right the choice.

Funny enough, makeup or skincare products are actually identity products but are less publicly observable. For these products, the quality attribute is more important, therefore, consumers may rely more on popularity labels to make the purchase decision.

4. Use social proof for gift shoppers

social proof gifts

Marketers should also consider if their products are being bought for the customers themselves or if they are buying the products for someone else. Those buying a gift for someone else will rely heavily on social proof cues to inform their decision.

If you’re unsure of what to buy for someone, you’ll be more inclined to buy something that you know a lot of people like, hence the effectiveness of social proof.

When buying for someone else, you want to decrease the risk of the person not liking the gift, social proof decreases this risk and, because of that, leads to increased purchase intentions. Knowing that a lot of people like or endorse a product will increase the chance of the person you’re buying a gift for will like it too.

5 Situations in which social proof doesn’t work

Now that we’ve covered several of the situations where social proof can be put to good use and why. It’s time to move on to those times where the result is less than ideal.

Social proof is not a one-size-fits-all approach. As said before, the primary condition that needs to be met is that someone is uncertain about what s/he should decide in a situation.

Next to the people who don’t believe you when you put a social proof message on the website because it seems fishy or simply unbelievable, there are also reasons it wouldn’t work even if your audience believes the message you show.

1. The audience is knowledgeable about the product

social proof knowledge

For example, if someone already knows what to do and has knowledge on the subject, it’s not very likely that the person will be persuaded otherwise by social proof.

The situation isn’t uncertain and, therefore, the person doesn’t need external cues to make a decision. The whole point of social proof is that people need guidance in situations when it’s unclear what to do.

Therefore, it’s better to let these people use their own knowledge to find what they’re looking for or entice them with a different persuasion technique.

2. The products are self-expressive

social proof self-expression

The same goes for products that are meant to be self-expressive (products with symbolic features or personal and social meanings) rather than functional products.


Because the point of self-expressive products is to enable an individual to express themselves so they stand out in the desired fashion. This stems from a romantic desire and a need for uniqueness that leads people to want to positively differentiate themselves.

You can think of the need for uniqueness as the desire to differentiate oneself from others through buying and using alternative consumer goods.

Romantic desire might lead social proof appeals (e.g., over a million sold) to backfire. It’s no wonder that brands like Burberry throw away excess clothing to make sure it stays a restrictive product. They make use of the opposite of social proof, which is exclusivity scarcity.

Individuals doing what “everyone else” is doing isn’t a good strategy to positively differentiate oneself. So, social proof appeals may become counter-persuasive when a person is motivated to maintain their self-expression.

Even when not being self-expressive, there is a high probability that someone will not go for the most popular option. Public consumption often involves self-presentation, leading consumers to choose products that present the self positively.

As a result, people may avoid both the majority and minority options to avoid being seen as either a sheep or a weirdo.

3. Audience seeks to counter conformity

countery conformity social proof

Gucci’s 2018 fall collection for men

A brand that likes to help individuals counter conformity is Gucci. It’s everything but common to see outfits like the one in the picture above. They embrace the non-conformity and should, as long as they do this, never use social proof messages for their products or their brand.

People may believe they will dislike things preferred by the majority in identity-relevant categories besides fashion. Some people experience cognitive dissonance when they buy an exclusive item that later becomes popular, as it makes it harder for that person to signal uniqueness.

Cognitive dissonance is the mental discomfort one gets when their actions don’t align with their beliefs. Or when that person has two contradicting beliefs.

For example, if someone bought an item (believes it is special) because it was exclusive, and it later becomes popular (meaning it’s not that special anymore), it will probably not sit well with them, eventually leading them to like it less.

before it was cool meme

Remember the meme about hipsters saying “I liked it before it was cool?” That was the schoolbook example of someone who experiences this feeling.

4. If only a small number of people endorse the product

small numbers social proof

Showing that two people have bought an item doesn’t necessarily show that it’s popular, considering alternatives have been bought over 20 times. Having social proof in place when there isn’t actually a lot going on will backfire.

Using small numbers for your social proof message can also hurt your purpose in both the short and long term. In the short term, people will think the product they’re looking for isn’t as hot as they’d hoped.

In the long term, it could even hurt your brand because the products people view are actually not that wanted and this can alter the perception of your brand.  

5. Negative Social Proof

negative social proof

It’s also not wise to use social proof for promoting behavior you don’t want. By showing that many people are doing the “bad” behavior, it gives the impression that it’s the norm. This norm indicates that it is normal behavior, even when it has been stated that the behavior is unwanted.


wikki social proof

Even Wikipedia gives off the wrong message when asking their readers to donate to their cause. By saying “Only a tiny portion of our readers give,” they’re telling their audience it’s normal not to give, making the message not very persuasive.


wikki email

Fun side note, in 2016 I once reached out to Wikipedia to point this out. Unfortunately, all I received was an email saying thanks for the suggestion… with no further adjustments to the message up to this day.

The influence of culture on social proof effects

Lastly, the effects of your social proof messages largely depend on the culture of your audience. For example, let's consider the cultural differences between collectivist and individualistic cultures.

But first, a quick definition by Hofstede himself:

“Individualism can be defined as a preference for a loosely-knit social framework in which individuals are expected to take care of only themselves and their immediate families.

Its opposite, Collectivism, represents a preference for a tightly-knit framework in society in which individuals can expect their relatives or members of a particular in-group to look after them in exchange for unquestioning loyalty”.

In plain language, individualists focus more on themselves and close connections and collectivists have more tight-knit communities and value the wisdom of the crowd. Needless to say, people with a collectivistic mindset are very likely to be persuaded by social proof because of their nature of experiencing unquestioning loyalty.

This doesn’t mean it wouldn’t work for individualistic countries, people are just more dependent on themselves and often do things without the need for a group to support them.  Therefore, individualistic people are more persuaded by those who are similar to them rather than simply seeking popularity cues to guide their decisions. Which, in itself, is a form of social proof.



All in all, social proof is a great strategy. But you need to know who and when to target. It’s not as magical as one might think but when used in the right context, social proof will help you to persuade your audience.

Coming out of this article, keep the following in mind:


  • Show the popularity of functional, non-identity/non-expressive products
  • Use social proof for products that are usually bought as gifts
  • Employ social proof for products that most people have little understanding of
  • Be aware of the culture that is surrounding your audience


  • Use it for people who know what they want or who are looking to counter conformity
  • Use social proof on items that express identity and could satisfy one’s need for uniqueness
  • Use small numbers as social proof
  • Use social proof to show how certain behavior is bad because it is done by a lot of people.


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