Regular readers will know that I'm generally pro-Amazon. However, Amazon must avoid two classic "Internet company" pitfalls moving forward:
1.) The temptation to try to be all things to all people. Brick-and-mortar businesses all realize that they need to define a limited, tightly focused business model and stick to it. Internet companies, by contrast, suffer from a constant temptation to expand into sidelines.
2.) Pay attention to cash flow: A decade and a half ago, thousands of dotcoms went bankrupt because they believed that the Internet was "special", and therefore, online companies weren't bound by the first need of any viable going concern: to generate a positive cash flow.
Amazon has been around since 1995. That's almost twenty years. It is no longer a "start-up", and it should not behave like one.