Amazon is managing growth rate following "flywheel" concept of pushing a giant, heavy flywheel, turn upon turn, building momentum until a point of breakthrough.
Amazon is not always able to accurately forecast growth rate. They base expense levels and investment plans on sales estimates. A significant portion of expenses and investments is fixed, and they are not always able to adjust spending quickly enough if sales are less than expected. Revenue growth may not be sustainable, and percentage growth rates may decrease. Revenue and operating profit growth depends on the continued growth of demand for the products and services offered by Amazon or sellers, and business is affected by general economic and business conditions worldwide. A softening of demand, whether caused by changes in customer preferences or a weakening of the U.S. or global economies, may result in decreased revenue or growth. Sales and operating results fluctuate for many other reasons, including due to factors described elsewhere in this section and the following: