The 'Liking' Principle in User Interface Design

by Jennifer Cardello on November 23, 2014

Summary: People prefer to say “yes” to individuals and organizations they know and like. Same goes for websites and other user interfaces.

A classic example of the liking principle is the old-fashioned Tupperware party (with its modern counterparts: the kitchen-gadget, jewelry, or wine-tasting party). The host of a Tupperware party was supposed to invite friends and acquaintances at her home and show them a variety of Tupperware containers. The guests could buy these and the host would receive a commission for all containers sold. Initially, the products were sold only via retail outlets, but they didn’t do well. In the late 1940’s, Tupperware began organizing “demonstration” parties. By 1951, Tupperware products were no longer offered at retail outlets because the parties generated far more sales. Why? Because people invited to parties bought the containers not because they needed or wanted them, but because they liked the host and they wanted her party to succeed and generate commissions. (They also felt obliged to reciprocate for being invited to the party.)

Stella & Dot facilitates accessory parties in people’s homes. When you become a stylist, you can plan parties and invite friends to shop. This situation takes perfect advantage of the liking principle – where consumers buy items because of their friendship with the hostess, not out of need.

Examples of Interface Patterns that Use the Liking Principle

Pictures of real people

In this example from Unbounce, real customer-service staff are pictured in a friendly and casual style. Photos of real people elicit empathy from customers who realize they are talking with a human being and may be more polite and tolerant.

Taking advantage of members’ networks

Rue La La is a flash-sale membership-based site. Current members can “refer” others to the site and receive credit when they purchase goods. The success of the Invite Friends program relies on the liking principle: that recipients will try it out to help their friend [whom they presumably like] earn the $10 credit.

Provide history: About Us

A study participant visiting the Amy’s Kitchen website said “They make a nice pizza; I think she’s local.” She then spent the next few minutes scouring the About Us section and to find out more about Amy. It turns out Amy wasn’t local, but the participant was touched by the family’s story. She will likely be reminded of this feeling next time she’s at the grocery store and it could contribute to a preference-driven sale

Background of the Liking Principle

The Liking Principle is one of 6 influencing principles coined by Dr. Robert Cialdini, a professor at Arizona State University famous for his 1984 book “Influence: The Psychology of Persuasion.” Cialdini’s book is a study of the psychology of compliance. As a psychology professor, he and his students conducted numerous research studies to identify and prove the 6 influencing principles discussed in his book.

Many social psychology studies have been conducted to determine the nature of liking. The following are a few of the drivers:

  • Similarity: We like people who are like us. Good salespeople will often mimick your accent, phrasing, and/or body language to gain your trust and make a deal.
  • Familiarity: Repeated positive interaction with a person, organization, or interface encourages liking.
  • Cooperation: We like people who want to help.
  • Association: We like people who share our values. For some this could be that a person or organization does work for a charity, for others it may be more status-revealing associations like owning a fancy watch or car. A friend who drives a new Tesla (cutting-edge electric car) gets endless thumbs-ups and smiles from strangers.
  • Praise: We really like people who compliment us. In fact, studies have shown that the compliment doesn’t even need to be perceived as genuine to have a positive effect. Cialdini’s book summarizes the findings of one such study conducted with men in North Carolina: “First, the evaluator who provided only praise was liked best by the men. Second, this was the case even though the men fully realized that the flatterer stood to gain from their liking him. Finally, unlike the other types of comments, pure praise did not have to be accurate to work. Positive comments produced just as much liking for the flatterer when they were untrue as when they were true” (p. 176).

Unlike scarcity and social proof (2 other influencing principles), which are typically used to speed up actions, liking of a company, website, or interface can linger and have long-term benefits. It can lead to customer retention and conversions at a later point.

Instances Where Liking Can Help

Warming users: We occasionally hear from our course attendees about negative interactions with internal users of systems like intranets and operational software. Including images of the support staff with short bios could reduce harsh confrontations.

For young companies: Early adopters tend to think of themselves as brand advocates. Getting a better sense of your individual employees makes them feel an even stronger bond.

For more established companies: Use liking techniques to encourage loyalty. Historical information can help and subtly reminding people of their familiarity and comfort with you (e.g., the high cost of change).

Testing Liking

The most significant risk with liking is using face images that, for some reason, do not resonate with your users. In studies, we have seen participants react negatively to some pictures of people; this type of reaction could have negative impacts on conversion. The best way to test imagery of this sort is to conduct usability testing. A/B testing is also an option if you are wondering about one set of faces versus another.


The key to effectively employing the liking principle is user research. If you don’t know your users well, it’s very difficult to anticipate what techniques (similarity, familiarity, cooperation, association, and praise) will have a positive impact. Research techniques such as surveys, interviews, and usability testing can all contribute data to this exploration.

For more on "liking" and other persuasion techniques, see our full-day Persuasive Web Design training course.



Robert B. Cialdini Influence: Science and Practice, Pearson Education Inc., 2009.

Share this article: Twitter | LinkedIn | Google+ | Email