User reviews have proven to be an effective sales driver, but there is more to it than just adding them to product pages. Once you start to get large amounts of reviews you need be able to sort them in a meaningful way for customers.

Usability expert Jared Spool has a great example of how Amazon managed to solve this problem for its customers and add $2.7bn to its bottom line.

In this article from The Economist last week, Google’s retail industry director John McAteer says that the amount of reviews is crucial for increasing conversions, with 20 the magic number, at which point the product becomes more attractive and inspires further reviews. 

However, once the number of reviews reaches a certain point, and users have too many to scroll through, then they need some help making more sense of them.

Amazon’s solution is described by Jared Spool in his latest article, and was as simple as adding the question: ‘was this review helpful to you?’ which helped Amazon to place the most relevant reviews, and therefore the most useful ones for conversion, at the top.

Amazon quietly bumps the three most helpful reviews to the top. It
tries to balance positive and negative reviews, so shoppers get a
balanced perspective. An interesting side effect is how these selected
reviews get more votes. If they are controversial (in that not everyone
agrees they were helpful), their ratio goes down, allowing the most
helpful reviews to bubble up past them. This makes it a self-managing system, letting the reviews people
find the most helpful to maintain their standing at the top of the
list. The result is an understated implementation that works great.

Other touches, such as allowing users to easily view the best negative or positive reviews, as well as some handy charts that summarise review ratings, make the large number of reviews manageable for users and more useful for Amazon.

Jared calculates that, since displaying the most helpful reviews has increased sales in the media products category by 20%, overall this feature was worth $2.7bn to Amazon, and after this example of a firm that made $300m by removing the need to register before checkout, shows how small tweaks can make a big difference.

This doesn’t necessarily apply to all retailers, as few attract the sheer numbers of reviews that Amazon, In fact, it’s hard to find too many UK e-commerce sites with a large number of reviews.

Kelkoo and Reevoo both ask if reviews were helpful, and this makes product pages easier for shopper to scan. Reevoo provides a useful summary of scores, and displays review in order of how helpful others found them: 

Reevoo reviews

On the Game website, there are a number of items with hundreds of reviews, but the retailer hasn’t provided the tools to sort them and to help shoppers make more use of them. In this example for Grand Theft Auto, there are 217 user reviews split across 40+ pages:

Game reviews

Having gathered so much user feedback, Game is not making the most of it, and this is a clear case where the ability to rate reviews as helpful or otherwise could make them a valuable resource for shoppers, and help increase conversions for the retailer.