Sales Loves Marketing

What is Social Proof?

Social proof is the tendency to copy what other people do or approve of, especially when we are unsure what to choose. In marketing, it means showing evidence that others already use and trust a product, such as reviews, case studies, customer logos and testimonials.

By Sales Loves Marketing teamOriginally written by Joran HofmanUpdated

Social proof is our habit of following other people when we are unsure what to do. If many people, or people like us, chose a product, we assume it is probably a good choice. Marketers use it by showing reviews, customer stories and other signs that a product is already trusted.

Where does the idea come from?

Psychologist Robert Cialdini coined the term in his 1984 book Influence, where it is one of his principles of persuasion. It is also known as informational social influence: we copy others because we think they know something we don't, not only to fit in.

Social proof is strongest when:

  • people are uncertain, for example when choosing between options they can't easily compare;
  • the others seem similar, such as companies of the same size or people in the same role;
  • the others seem to know more, such as experts or experienced users.

Google's 2020 "messy middle" research, run with The Behavioural Architects among UK shoppers, tested six biases that shape purchase decisions, and social proof was one of them. It notes that online reviews and star ratings have made social proof an easy shortcut for buyers.

What are the types of social proof?

  • User: reviews, ratings and testimonials from customers.
  • Expert: recommendations from industry experts, analysts or trusted publications.
  • Celebrity or influencer: endorsements from well-known people.
  • Crowd: numbers that show popularity, such as how many companies use a product.
  • Peer: recommendations from friends, colleagues or people in the same network.
  • Certification: seals and certificates from independent bodies, such as security standards or awards.

Why does social proof matter in B2B marketing?

B2B purchases are often expensive and hard to undo, and the buyer has to justify the choice to colleagues. Evidence that similar companies succeeded with your product lowers that risk. It matters most in the middle of the funnel, when buyers compare vendors.

Good places to use it:

  • Landing and pricing pages: customer logos, short quotes and review ratings near the call to action.
  • Sales emails and proposals: a case study from the prospect's industry.
  • Sign-up forms: a short line on who already uses the product.
  • Comparison pages: independent review scores, with the source named.

Test placements with conversion rate optimization rather than adding badges everywhere.

What are the rules on reviews and testimonials?

In the US, the FTC's rule on consumer reviews and testimonials took effect on 21 October 2024. It bans fake or false reviews and testimonials, offering incentives on the condition that a review is positive or negative, and buying fake followers or other fake signs of influence. Insider reviews, for example from employees, must clearly disclose the relationship.

The FTC's Endorsement Guides, revised in 2023, add that endorsements must reflect the endorser's honest opinion, and that payments, free products or other connections must be disclosed clearly.

Use real customers, get their permission and keep quotes accurate.

Frequently asked questions

Who came up with the term social proof?

Psychologist Robert Cialdini coined it in his 1984 book Influence, where it is one of his principles of persuasion. Psychologists also call it informational social influence.

What are examples of social proof in B2B marketing?

Customer reviews on independent review sites, case studies with named customers, logos of well-known clients, testimonials from people in the buyer's role, security certifications, awards and the number of companies using the product.

Is it legal to pay for reviews?

In the US, the FTC rule on consumer reviews and testimonials, in force since October 2024, bans fake reviews and bans offering incentives that require a review to be positive or negative. Reviews from employees or other insiders must clearly disclose the relationship, and paid endorsements must be disclosed under the FTC's Endorsement Guides.