It's worth noting that the two biggest population centers in the US -- the East and West Coasts -- are being hammered by weather. In the Washington, DC, area, we have nearly three feet of snow in much of the region. Traffic isn't snarled because there isn't any. Nobody can get out and everything is closed.
On the West Coast, torrential rain is causing power failures, traffic woes, etc. And then there's the Super Bowl, which is sucking up most of the eyeballs everywhere else.
Many advertisers are quick to snuff budgets when shoppers aren't out shopping. Wouldn't be surprising if that was happening the last few days.