In the Buffer article, 6 Types of Social Proof by Alfred Lua

Before we go through the strategies, let’s go through what social proof is and the science behind it. Here’s how social proof is being described on Wikipedia:

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

According to Robert Cialdini, who studied the principle of social proof in-depth in his book, Influence: The Psychology of Persuasion, “we view a behavior as more correct in a given situation to the degree that we see others performing it”. So often in situations where we are uncertain about what to do, we would assume that the people around us (experts, celebrities, friends, etc.) have more knowledge about what’s going on and what should be done.

On top of that, we often make judgments based on our overall impression of someone — A.K.A. the halo effect (named by psychologist Edward Thorndike). For example:

• We think anything that experts use is great because they are probably more knowledgeable than us in their area of specialization.
• We buy products endorsed by celebrities because we want to look like them.
• We trust user reviews because they have experienced the product or service, unlike ourselves.

In general, there are six types of social proof¹.

1. Expert: Expert social proof is when an expert in your industry recommends your products or services or is associated with your brand. Examples: a Twitter shoutout by an expert or having an expert on your Twitter chat.
2. Celebrity: Celebrity social proof is when a celebrity endorses your products. Examples: an Instagram post or tweet about your product by a celebrity or influencer.
3. User: User social proof is when your current users recommend your products and services based on their experiences with your brand. Examples: praises on social media or positive ratings on review sites.
4. The wisdom of the crowd: This type of social proof is when a large group of people is seen to be endorsing your brand. Examples: having thousands of customers or millions of followers on your social media profiles.
5. The wisdom of your friends: This type of social proof is when people see their friends approve your product. Examples: seeing their friends use your product or follow you on social media.
6. Certification: This type of social proof is when you are given a stamp of approval by an authoritative figure in your industry. Examples: the blue checkmark on Twitter or Facebook.