How to use ‘social proof’ to drive your online conversion

by Jeroen Haijen - December 17, 2014

Our Facebook timeline has just recovered from the ‘Ice Bucket Challenge’. Lots of friends, colleagues and relatives voluntarily got a bucket of ice-cold water over their heads supposedly for a good cause. Each day new videos were posted by other acquaintances taking part in the challenge. But why did everyone kept on pouring water?

Similar to most crazes, the Ice Bucket Challenge proved our peers have a strong influence on each of us. We have a natural tendency to follow the lead of other people. This is especially the case when:

  • We perceive them as similar to ourselves,

  • A lot of people behave in the same way,

  • Circumstances are uncertain or unfamiliar.

This inborn desire to conform to others is called ‘social proof’ and is a key principle of persuasion as first defined by Cialdini. It is a powerful way to persuade your users to take a desired action.

You too can add social proof to your online communications and optimize your conversion through the following effective tactics:

  • Ratings & reviews

  • Testimonials

  • Social media likes and recommendations

  • Wisdom of the crowd

  • Defaults and filters

  • Social moderation

Ratings & Reviews

Ratings and reviews work on two different levels. Ratings allow a quick scanable comparison by means of a valuation (e.g. stars, hearts). Reviews on the other hands offer personal insights. This combination provides a powerful persuasive component.

Examples: Pioneer, Coolblue


People are influenced by the consensus of people around them and can change their opinion just to match the opinion of others. Testimonials emphasis only people who agree with your message or support your products and services.

Social media recommendations

Traditional testimonials were reinvented via social media. You can collect followers, likes and recommendations that provide social proof to your website visitors.

Since these recommendations can come from peers that are known and verified, this social proof can better persuade your prospects.

Wisdom of the crowd (safety in numbers)

You can convince your users by showing how many people have already signed up.

Example: Basecamp

Another way to convince your customers is by displaying who is already a client. Especially if they are well known and respected companies.

Who can resist downloading an app when it is the #1 app of all time!

Defaults and filters

nother proven way to leverage conversion via social proof is by using 'the default'.Example: Coolblue pre-sets their filter to 'most sold'

Or you can provide filters and suggestions that allow you to browse what other customers have bought too.

Avoid using defaults just to trick users and increase the cost. for example automatically selects a period of 2 years including a domain privacy cost. It is hard to spot and remove this default once it has been added.

Social moderation

On people are invited to vote on what to sell in the future. The top choices receive a badge. Styles with this particular badge sell at a double speed.

On you have full access to qualitative reviews and scores for movies and series. The site has a full-blown community and moderation algorithm that allows users to write and score movies. The reviews are also scored to guarantee quality. Reviews, scores and recommendations of friends are displayed to additionally engage users.


It is possible only a few people really use the social proof elements to give their opinion. In that case it is good to offer alternatives. For example: You can invite customers to write a review to receive a discount or voucher. Meanwhile, you can buy professional product reviews to display on your website when you did not have received any customers reviews yet.

Always be aware that your social proof is realistic. When it is conceived as artificial or even contrived, it will hurt your conversion rates. For example, to illustrate a testimonial, use realistic-looking photos of customers interacting with your product rather than a posing model.

Do not blindly follow all the best practices and plaster your pages with all social proof techniques. Too many components can clutter a website and make the interface complicated and distracting. Wisely choose the elements you think will work best on your website and always optimize via A/B testing.

Traditional user testing can help you as well to check if the components are not too overwhelming and understand why something works or not.


We discussed a number of proven tactics to improve your conversion rates via social proof. However, use them wisely and always evaluate if they effectively increase persuasion, emotion and trust and really optimize conversion.

Jeroen Haijen

UX Designer