Likely the biggest hit to productivity this time of year.
Preparing for disasters is likely to get in the way of one's Christmas shopping while at work. Personally, I think some of this online shopping is OK for the purchase of one (1) item that is some super-duper deal on a particular day. The workplace is not the place to spend hours perusing deals being offered online. But then, I'm likely an old fogey when it comes to this type of thing.
See the infograph below for some basic statistics for shopping at work.