December sales were up 4.1% to December 2015 due strong auto sales with aggressive year end promotions.

The top 3 growth businesses were internet retailers, health stores and restaurants/bars:

Non-store/online retailers posted a strong 13.2% gain over last year. An acceleration from the last few months.
Motor vehicle dealers posted the second largest growth rate with 7.2% year over year growth.
Heath and personal care stores posted the third largest (excluding gasoline) increase 6.2% year over year monthly gain.
One point to note is the positive yet declining growth rate trend in food services & drinking places.

On the downside, the bottom 3 remained the same:

Department Stores multi-decade decline continued with a sizable 8.4% decline.
Sporting goods, hobby, book and music stores saw a decline of 3.6%.
The Electronics vacuum of sales to online continues with a decline of 2.4%.

Strong auto sales brought rosier sales than expected, nothing new here in terms of shifting sales to online but the degradation in restaurant sales growth is a trend worth noting.