How Amazon made $2.7bn with one small tweak

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.