How Amazon drove $2.7 billion in incremental sales through clever user interface design

Jared Spool has written a fascinating story on uie.com about the importance of a single question that Amazon incorporated into its user interface design: “Was this review helpful to you?” At a stroke this meant the reviews users saw weren’t simply arranged in chronological order, but in order of helpfulness. It’s also rather stunning to see what a small percentage of people bother to write or vote on the helpfulness of reviews. For Harry Potter and the Deathly Hallows, which sold over 4 million copies on Amazon, fewer than 3,300 people wrote reviews, which works out to about one out of every 1,300 people who purchased the book. The numbers get even smaller when you look at the number of people who vote on the helpfulness of reviews. In fact, the most helpful review got only 566 votes. 

Small though the numbers seem, according to Spool, “one out of every five customers decides to complete the purchase because of the strength of the reviews.” If you do the math, that works out to an extra $2.7 billion to Amazon’s bottom line.  

Agencies and clients alike should note the importance of customer reviews (both positive and negative) not only in the world of e-commerce, but in the world of branding. If you try to hide negative comments about your brand, you’re destined to wind up with the credibility of a Cuban election. When Castro gets 99.7% of the vote, we know something isn’t right. The same is true for your brand.