I haven't seen anyone mention another key PR benefit of announcing this early: to take the wind out of Google announcing delivery via self-driving car. Google

I haven't seen anyone mention another key PR benefit of announcing this early: to take the wind out of Google announcing delivery via self-driving car. Google is probably more threatening to Amazon than any other company, and they have a clear interest in attacking physical good delivery in a manner that is deflationary relative to Amazon - almost certainly by using self-driving vehicles to provide local delivery to existing retailers, gaining access to the inventory databases in the process. Google likes to do PR stunts to project an image of futuristic technological leadership. It looks like they have a competitor.