Only one thing would serve to turn amazon into a efficient cash and profit machine; wall street holding them properly accountable. This ingrained culture of spending to gain sales regardless of efficiency discipline will only be broken by a wicked sell-off of the stock.
Playing for a longer term time frame is generally a healthy strategic posture to take when managing a start-up but Amazon has slipped into very bad habits. Each spending phase ends up with lower and lower margins and longer investment cycles. The latest "investment " cycle is full of highly paid engineers, employees of all strips and massive infrastructure with sticky ongoing cost commitment.
Wall street is keeping the patient well fed and medicated and hopes for heeling but the patient doesn't realize they are sick!