The past year or so has been a tough time to be an Amazon (NASDAQ: AMZN) shareholder. After the stock peaked at the height of the pandemic, tough economic conditions have weighed on it, as consumer spending was hampered by high inflation and rising interest rates. In the face of slowing growth and a bid to increase profitability, the e-commerce leader has quietly -- and without much fanfare -- made a change behind the scenes that could potentially speed up its deliveries, while also bolstering the bottom line.