Tactic #296 - If connected via Facebook, indicate how many friends have purchased or signed up

Tactic_If connected via Facebook, indicate how many friends have purchased or signed up


If you offer your customers the option to sign in using Facebook then make the most of this advantage. Indeed, using Facebook is a good way to quickly access data about a customer but that's not the only benefit. You can also use it to help persuade them to make a purchase, by displaying those of their Facebook friends who have liked, used, talked about, or purchased the products from your site. When we are unsure on which decision to make, studies show that we tend to imitate others' behaviour - and none will be more persuasive than that of people we know. We will automatically think that if one of our friends purchased or liked a particular product, then it must be good. The product is given immediate credibility and extra desirability, which will influence conversion rate.


  • Social Proof (Sherif, 1935; Asch, 1956)
  • Mere-exposure Effect (Fechner, 1875; Zajonc, 1960)

The Research

Social Proof

This principle was first explored by social psychologist Sherif in 1935, and later developed by Asch in 1956. Social proof is the idea that we are intrinsically driven to conform and so will often be influenced to copy others’ decisions and actions, especially when we are hesitating or feel as though we don’t have enough information of our own. We tend to assume that surrounding people possess more knowledge of any given situation and that the actions of others therefore reflect correct behaviour.

This social proof principle is driven by our natural desire to behave “correctly” under most circumstances: we are social and tribal beings, and what others think, say or do is important to us and can be a powerful motivator. This principle also relies on a sense of ‘safety in numbers’, meaning if we are all doing the same thing then we feel we are protected and validated in some way. For example, we’re more likely to work late if others in our team are doing the same, put a tip in a jar if it already contains money, or eat in a restaurant if it’s busy. We assume that if others are behaving a certain way then it must be for a reason: the restaurant is good, the service deserves tipping, the work needs to be finished, etc.

Social proof also applies to marketing and sales. For example, online marketing strategies such as displaying validation logos, subscriber count, social shares or testimonials on a website are all based on the social proof principle. The amount of followers, views, likes, subscribers or past satisfied customers that a user sees positively affects how they will perceive the website. It’s for this reason that we consult TripAdvisor for hotels and restaurants, Consumer Reports before making purchases, Kayak for flight choices, Yelp for eating out, and so on. We want to check and validate our decisions before we make them to ensure we are adhering to the same behaviour as our peers and put a lot of stock in what their testimonials and actions tell us.

Mere-exposure Effect

First explored by Gustav Fechner in the 19th Century, the Mere-exposure Effect was then further developed between 1960-1990 by renowned psychologist Robert Zajonc, who discovered that people would react more favourably to certain stimuli the more they were exposed to it.

Humans are naturally more comfortable with and positive towards things that they are familiar with and so it is both possible to elicit a positive reaction from someone by presenting them with something familiar or indeed by making something familiar to them through repeated exposure. One of Zajonc’s experiments consisted of showing people nonsense characters that looked like Chinese symbols and asking them to guess the meaning. After they had been shown the same symbols several times, the meanings offered become more and more positive as, even subconsciously, people had become more familiar with those symbols.

In marketing, the Mere-exposure Effect can be used in many ways. Of course, you want to stand out to a certain extent but being too different from other brands that people are already familiar with could result in distrust. You can make your own brand appear instantly more familiar by basing your logo, design or features on other similar brands that already have a loyal following. This similarity, even if it is slight and will only tap in to the customer’s subconscious, will instantly make people feel more trustful of your brand. Another way is to utilise a familiar figure to help make this connection more instantaneous; for example, when brands use a celebrity endorsement it is so successful, not because that celebrity is an expert on the product or industry or because we even trust their judgment, but because they are a familiar face to us and therefore we are immediately drawn towards them and the product they are representing.

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