Join Chris Nodder for an in-depth discussion in this video Social proof, part of Persuasive UX: Creating Credibility.
We typically care what our friends think about us and our activities. We're proud when our friends praise us for something we've done and upset if our friends disapprove. Much of our behavior is determined by our impressions of what's the correct thing to do. Our impressions are based on what we observe others doing. Those others don't have to be our friends. In a new situation, you might well follow the cues of total strangers. Most of those strangers could also be new to the environment, but you still make the assumption that they have a deeper understanding of the situation.
Experts, celebrities, existing customers, even the wisdom of the crowd, can all serve as drivers for how we behave. This influence is known as social proof, the idea that if other people are doing it, it must be right. If we see a tip jar full of bills, we're more likely to tip. If we see a nightclub with a line outside, we're more likely to think it's a popular venue. If we see a restaurant full of happy people, we're more likely to think that eating a meal there would be worthwhile. That's why baristas prime their tip jars in cafes, why night clubs keep a slow-moving line outside, even if the club's quiet inside, and why restaurants seat people at the window seats first thing in the evening.
In 1969, Stanley Milgram was running studies looking at conformance. He had a paid helper stand on a busy sidewalk and look up at the empty sky. He noted that around 40% of the people passing would also look up. With two people, that number rose to 60%. When he paid four people to stand together and look up, around 80% of people passing would also look up. If more people are doing something, it lends additional credence to the activity.
If you hear about the same product from several different sources, you tend to attribute more positive views to it than to a product you were unfamiliar with. In other words, familiarity doesn't breed contempt, it breeds reassurance. Give customers several different types of information that all point to the conclusion that you want them to reach. You might want to provide white papers of case studies, recommendations for complimentary products or accessories, and product reviews. You're product reviews should be placed at locations on the site where they'll be seen by new users, people shopping for infrequent or unfamiliar purchases, or people seeking expertise.
You can also give indications of how popular a particular item is, such as number sold, number left in stock, or even a sold out label. Telling people that something is unavailable may seem crazy, but think about it for a second. What better social proof that an item is worth having than the fact that people are struggling to get a hold of it. In fact, one of the earliest successful uses of social proof in persuasive design was when the TV shopping channels changed their pitch from the words, operators are standing by to take your call, to, if all our operators are busy, please try again soon.
The social proof implication in the revised message was that the lines will be busy because the products were so popular, so you'd better call now if you wanted to get through. Testimonials are another type of social proof. If you offer testimonials, make sure they come from someone who appears qualified to make the statements, and that you give enough details about that individual that the reader can validate that they exist. Because the information from each of these sources complements the other sources, and because they appear in different places around the site, users tend not to notice that the same basic message is being repeated to them in different ways, each time.
The best forms of social proof come from outside the direct sphere of influence that a site has. Reading positive statements about a product or company on a supposedly neutral third-party site can have greater social proof outcomes than reading the same statements on the company's own site. For that reason, solicit reviews on third-party sites or get people to use social media to spread the word. One of the cleverest ways of ensuring that only good news gets spread is to ask people to tweet about their experiences if they feel good about the product, but promise them that you'll address their issues if they email or call you with any problems that they have.
That way, you can deal with the issues without them becoming public.
Want more persuasive design techniques? Check out the rest of the courses in Chris Nodder's Persuasive UX series.