Inside the black box of Amazon returns

Retailers' costs for managing returns are rising. Ronny Hartmann/picture alliance via Getty Images

E-commerce may make shopping more convenient, but it has a dark side that most consumers never see.

Say you order an electric toothbrush for Father’s Day and two shirts for yourself from Amazon. You unpack your order and discover that the electric toothbrush won’t charge and only one shirt fits you. So, you decide to return the unwanted shirt and the electric toothbrush.