>>I am seeing some popular and high-demand products missing from the shelves for days on end.<<
That is probably the result of the international economy. We have far less ships unloading from China today compared to 2007. Their problem these days is determining which ships to sell to the steel yards and where to anchor them while their waiting. All the while, they are ordering super carriers with delivery dates out in the future.
These are some of the more interesting websites, IMO
http://www.marinetraffic.com/ais/
http://www.crowley.com/News-and-Media/Press-Releases
http://www.hellenicshippingnews.com/
Is that what you would call efficiency?
That's a fair question, but the efficiency of fast truck delivery is not free: it comes at the cost of greatly increased commuting time (reduced productivity, less time spent with families) for every American on a road clogged with truck traffic.