Mind you, the solution could have been a lot simpler: set a date in early December where you can guarantee pre-Christmas delivery. I'd say December 7 as the latest date you can order for guaranteed delivery.
That is "old thinking" and guaranteed to lose customers to brick and mortar retail. Why should Amazon suffer because of the deficiencies of the package delivery industry?
Amazon is redefining retail. Competitors need to get on the train or get run over.
not a 2016 solution. Not everyone gets it together by early december. Amazon has found a niche. UPS will survive for business deliveries. It will impact the biggies to some extent however until by packages can be beamed directly to my home.