“The data we’d collected over the years through many tests just reinforced this. Shipping promotions drove significantly higher growth than any other type of promotion. The perceived value of free shipping was higher than straight discounting of product prices. Put another way, if the average discount of a free shipping promotion was 10 percent, we’d see significantly more demand lift (called elasticity) by offering free shipping than by discounting product prices by 10 percent. It wasn’t even close. Free shipping drove sales. We just had to figure out a sustainable way to offer free shipping.”