It is once more shown that looking at what can be valuable for the users and then implement this in the design, can have a huge impact. Jared M. Spool wrote an article in which he explained how Amazon increased its sales with 20% by ‘just’ adding one simple question at the at the bottom of a review: ‘was this review helpful to you, yes / no?’ .
To read the full article of Jared Spool: http://cli.gs/yBHTmD