Liking and similarity

We are more persuaded by people who are like us.

Social influence Mainly on Product pages
Where it applies

Two of the eight page areas.

HomepageAlso applies CategoryNot typical SearchNot typical ProductMainly here CartNot typical CheckoutNot typical Post-purchaseNot typical

Not usually a sitewide principle. See everything at work on Product pages

How to use it

Five ways to use it, and two to avoid.

  • Show reviewer attributes on reviews, such as size, skin type, use case and location.
  • Let shoppers filter reviews by those attributes.
  • Use relatable customer imagery.
  • Tell the founder story.
  • Leave reviews anonymous where you cannot match reviewers to the shopper.
  • Avoid: showing reviewers who are visibly unlike the shopper, which can reduce persuasion.
  • Avoid: displaying reviewer attributes customers have not knowingly agreed to share, as they are personal data.
What the research found

Similarity strongly predicts liking. On Amazon, identified reviewers were linked to higher sales.

Shoppers assume anonymous reviewers share their tastes.

A meta-analysis of 313 studies found similarity strongly predicted liking (r = .47 actual, .39 perceived), though in existing relationships only perceived similarity mattered. Shoppers assume anonymous reviewers share their tastes and are less persuaded by clearly dissimilar ones. On Amazon, reviews disclosing reviewer identity were linked to higher sales, more so when reviewer and shopper shared a location.

Key research

Five sources, each checked.

Last reviewed

Montoya, Horton & Kirchner (2008)Meta-analysis Is actual similarity necessary for attraction? A meta-analysis of actual and perceived similarity J. Social and Personal Relationships Read the source Naylor, Lamberton & Norton (2011) Seeing Ourselves in Others: Reviewer Ambiguity, Egocentric Anchoring, and Persuasion J. Marketing Research Read the source Forman, Ghose & Wiesenfeld (2008) Examining the Relationship Between Reviews and Sales: The Role of Reviewer Identity Disclosure in Electronic Markets Information Systems Research Read the source Byrne (1971) The Attraction Paradigm (New York: Academic Press, 1971) The Attraction Paradigm Read the source Burger, Messian, Patel, del Prado & Anderson (2004) What a Coincidence! The Effects of Incidental Similarity on Compliance Personality and Social Psychology Bulletin Read the source
Before you use it · UK law

Showing reviewers who are unlike the shopper can reduce persuasion. Reviewer attributes are personal data, so collect and display only what customers have knowingly agreed to share.

This is simply a pointer to check, not legal advice. Seek legal advice before you put this principle into action.